Update bundled libpng to version 1.6.38

With this update, there are no longer any diffs to upstream
libpng. Hence, the qtpatches.diff file is removed. Details:

- #define _CRT_SECURE_NO_DEPRECATE: Done on compiler cmdline instead
- #undef PNG_BUILD_DLL: For our usecase, that only caused PNG_IMPEXP
  to be defined to an empty string. Done on compiler cmdline instead.
- #ifdef for WinCE: dead platform.
- A memory leak fix: Included in upstream 1.6.38.

[ChangeLog][Third-Party Code] libpng was updated to version 1.6.38

Pick-to: 6.4 6.2 5.15
Change-Id: I229db30e1dd54c209dc93e76d11e6fdb1f7adbdb
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

21 files changed, 173 insertions, 252 deletions

diff --git a/src/3rdparty/libpng/ANNOUNCE b/src/3rdparty/libpng/ANNOUNCE
index ecf9c7043b..9c9bb18918 100644
--- a/src/3rdparty/libpng/ANNOUNCE
+++ b/src/3rdparty/libpng/ANNOUNCE
@@ -1,5 +1,5 @@
-libpng 1.6.37 - April 14, 2019
-==============================
+libpng 1.6.38 - September 14, 2022
+==================================
 
 This is a public release of libpng, intended for use in production code.
 
@@ -9,13 +9,13 @@ Files available for download
 
 Source files with LF line endings (for Unix/Linux):
 
- * libpng-1.6.37.tar.xz (LZMA-compressed, recommended)
- * libpng-1.6.37.tar.gz
+ * libpng-1.6.38.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.38.tar.gz
 
 Source files with CRLF line endings (for Windows):
 
- * lp1637.7z (LZMA-compressed, recommended)
- * lp1637.zip
+ * lp1638.7z (LZMA-compressed, recommended)
+ * lp1638.zip
 
 Other information:
 
@@ -25,20 +25,13 @@ Other information:
  * TRADEMARK.md
 
 
-Changes since the previous public release (version 1.6.36)
+Changes since the previous public release (version 1.6.37)
 ----------------------------------------------------------
 
- * Fixed a use-after-free vulnerability (CVE-2019-7317) in png_image_free.
- * Fixed a memory leak in the ARM NEON implementation of png_do_expand_palette.
- * Fixed a memory leak in pngtest.c.
- * Fixed two vulnerabilities (CVE-2018-14048, CVE-2018-14550) in
-   contrib/pngminus; refactor.
- * Changed the license of contrib/pngminus to MIT; refresh makefile and docs.
-   (Contributed by Willem van Schaik)
- * Fixed a typo in the libpng license v2.
-   (Contributed by Miguel Ojeda)
- * Added makefiles for AddressSanitizer-enabled builds.
- * Cleaned up various makefiles.
+ * Added configurations and scripts for continuous integration.
+ * Fixed various errors in the handling of tRNS, hIST and eXIf.
+ * Implemented many stability improvements across all platforms.
+ * Updated the internal documentation.
 
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
diff --git a/src/3rdparty/libpng/CHANGES b/src/3rdparty/libpng/CHANGES
index f0b0a9342c..9a86869681 100644
--- a/src/3rdparty/libpng/CHANGES
+++ b/src/3rdparty/libpng/CHANGES
@@ -2295,7 +2295,7 @@ Version 1.4.0beta58 [May 14, 2009]
   Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
 
 Version 1.4.0beta59 [May 15, 2009]
-  Reformated sources in libpng style (3-space intentation, comment format)
+  Reformated sources in libpng style (3-space indentation, comment format)
   Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
   Added sections about the git repository and our coding style to the
     documentation
@@ -3886,7 +3886,7 @@ Version 1.6.0beta06 [January 24, 2012]
 Version 1.6.0beta07 [January 28, 2012]
   Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
     compiler issues slightly different warnings from those issued by the
-    current vesions of GCC. This eliminates those warnings by
+    current versions of GCC. This eliminates those warnings by
     adding/removing casts and small code rewrites.
   Updated configure.ac from autoupdate: added --enable-werror option.
     Also some layout regularization and removal of introduced tab characters
@@ -6103,6 +6103,12 @@ Version 1.6.37 [April 14, 2019]
   Added makefiles for AddressSanitizer-enabled builds.
   Cleaned up various makefiles.
 
+Version 1.6.38 [September 14, 2022]
+  Added configurations and scripts for continuous integration.
+  Fixed various errors in the handling of tRNS, hIST and eXIf.
+  Implemented many stability improvements across all platforms.
+  Updated the internal documentation.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
 Subscription is required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
diff --git a/src/3rdparty/libpng/CMakeLists.txt b/src/3rdparty/libpng/CMakeLists.txt
index 95705fa47a..4f8170bd02 100644
--- a/src/3rdparty/libpng/CMakeLists.txt
+++ b/src/3rdparty/libpng/CMakeLists.txt
@@ -28,6 +28,8 @@ qt_internal_add_3rdparty_library(BundledLibpng
     DEFINES
         PNG_ARM_NEON_OPT=0
         PNG_POWERPC_VSX_OPT=0
+        PNG_IMPEXP=
+        _CRT_SECURE_NO_DEPRECATE
     PUBLIC_INCLUDE_DIRECTORIES
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
diff --git a/src/3rdparty/libpng/INSTALL b/src/3rdparty/libpng/INSTALL
index 4c17022515..d3aaa28842 100644
--- a/src/3rdparty/libpng/INSTALL
+++ b/src/3rdparty/libpng/INSTALL
@@ -128,16 +128,18 @@ Your directory structure should look like this:
           README
           *.h, *.c  => libpng source files
           CMakeLists.txt    =>  "cmake" script
+          ci
+             ci_*.sh
           configuration files:
              configure.ac, configure, Makefile.am, Makefile.in,
              autogen.sh, config.guess, ltmain.sh, missing, libpng.pc.in,
              libpng-config.in, aclocal.m4, config.h.in, config.sub,
-             depcomp, install-sh, mkinstalldirs, test-pngtest.sh
+             depcomp, install-sh, mkinstalldirs, test-pngtest.sh, etc.
           contrib
              arm-neon, conftest, examples, gregbook, libtests, pngminim,
              pngminus, pngsuite, tools, visupng
           projects
-             cbuilder5, owatcom, visualc71, vstudio, xcode
+             owatcom, visualc71, vstudio
           scripts
              makefile.*
              *.def (module definition files)
@@ -145,7 +147,7 @@ Your directory structure should look like this:
           pngtest.png
           etc.
       zlib
-          README, *.h, *.c contrib, etc.
+          README, *.h, *.c, contrib, etc.
 
 If the line endings in the files look funny, you may wish to get the other
 distribution of libpng.  It is available in both tar.gz (UNIX style line
@@ -153,28 +155,27 @@ endings) and zip (DOS style line endings) formats.
 
 VI. Building with project files
 
-If you are building libpng with MSVC, you can enter the
-libpng projects\visualc71 or vstudio directory and follow the instructions
-in README.txt.
+If you are building libpng with Microsoft Visual Studio, you can enter
+the directory projects\visualc71 or projects\vstudio and follow the
+instructions in README.txt.
 
-Otherwise enter the zlib directory and follow the instructions in zlib/README,
-then come back here and run "configure" or choose the appropriate
-makefile.sys in the scripts directory.
+Otherwise, enter the zlib directory and follow the instructions in
+zlib/README, then come back here and run "configure" or choose the
+appropriate makefile in the scripts directory.
 
 VII. Building with makefiles
 
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example
 
-MSDOS example:
+UNIX example:
 
-    copy scripts\makefile.msc makefile
-    copy scripts\pnglibconf.h.prebuilt pnglibconf.h
+    cp scripts/makefile.std Makefile
+    make
 
-UNIX example:
+Windows example:
 
-    cp scripts/makefile.std makefile
-    cp scripts/pnglibconf.h.prebuilt pnglibconf.h
+    nmake -f scripts\makefile.vcwin32
 
 Read the makefile to see if you need to change any source or
 target directories to match your preferences.
@@ -197,30 +198,27 @@ do that, run "make install" in the zlib directory first if necessary).
 Some also allow you to run "make test-installed" after you have
 run "make install".
 
-VIII. Configuring libpng for 16-bit platforms
-
-You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more than 64K at a time.  Even if you can, the memory
-won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
+VIII. Configuring for DOS and other 16-bit platforms
 
-IX. Configuring for DOS
+Officially, the support for 16-bit platforms has been removed.
 
 For DOS users who only have access to the lower 640K, you will
 have to limit zlib's memory usage via a png_set_compression_mem_level()
 call.  See zlib.h or zconf.h in the zlib library for more information.
 
-X. Configuring for Medium Model
+You may be or may not be in luck if you target the "large" memory model,
+but all the smaller models ("small", "compact" and "medium") are known
+to be unworkable.  For DOS users who have access beyond the lower 640K,
+a "flat" 32-bit DOS model (such as DJGPP) is strongly recommended.
 
-Libpng's support for medium model has been tested on most of the popular
-compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
-defined, and FAR gets defined to far in pngconf.h, and you should be
-all set.  Everything in the library (except for zlib's structure) is
-expecting far data.  You must use the typedefs with the p or pp on
-the end for pointers (or at least look at them and be careful).  Make
-note that the rows of data are defined as png_bytepp, which is
-an "unsigned char far * far *".
+For DOS users who only have access to the lower 640K, you will have to
+limit zlib's memory usage via a png_set_compression_mem_level() call.
+You will also have to look into zconf.h to tell zlib (and thus libpng)
+that it cannot allocate more than 64K at a time.  Even if you can, the
+memory won't be accessible.  Therefore, you should limit zlib and libpng
+to 64K by defining MAXSEG_64K.
 
-XI. Prepending a prefix to exported symbols
+IX. Prepending a prefix to exported symbols
 
 Starting with libpng-1.6.0, you can configure libpng (when using the
 "configure" script) to prefix all exported symbols by means of the
@@ -231,7 +229,7 @@ identifier).  This creates a set of macros in pnglibconf.h, so this is
 transparent to applications; their function calls get transformed by
 the macros to use the modified names.
 
-XII. Configuring for compiler xxx:
+X. Configuring for compiler xxx:
 
 All includes for libpng are in pngconf.h.  If you need to add, change
 or delete an include, this is the place to do it.
@@ -243,7 +241,7 @@ As of libpng-1.5.0, pngpriv.h also includes three other private header
 files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
 that previously appeared in the public headers.
 
-XIII. Removing unwanted object code
+XI. Removing unwanted object code
 
 There are a bunch of #define's in pngconf.h that control what parts of
 libpng are compiled.  All the defines end in _SUPPORTED.  If you are
@@ -282,7 +280,7 @@ library to fail if they call functions not available in your library.
 The size of the library itself should not be an issue, because only
 those sections that are actually used will be loaded into memory.
 
-XIV. Enabling or disabling hardware optimizations
+XII. Enabling or disabling hardware optimizations
 
 Certain hardware capabilities, such as the Intel SSE instructions,
 are normally detected at run time. Enable them with configure options
@@ -332,7 +330,7 @@ or disable them all at once with
 
     cmake . -DPNG_HARDWARE_OPTIMIZATIONS=no
 
-XV. Changes to the build and configuration of libpng in libpng-1.5.x
+XIII. Changes to the build and configuration of libpng in libpng-1.5.x
 
 Details of internal changes to the library code can be found in the CHANGES
 file and in the GIT repository logs.  These will be of no concern to the vast
@@ -423,7 +421,7 @@ $PREFIX/include directory).  Do not edit pnglibconf.h after you have built
 libpng, because than the settings would not accurately reflect the settings
 that were used to build libpng.
 
-XVI. Setjmp/longjmp issues
+XIV. Setjmp/longjmp issues
 
 Libpng uses setjmp()/longjmp() for error handling.  Unfortunately setjmp()
 is known to be not thread-safe on some platforms and we don't know of
@@ -441,7 +439,7 @@ This requires setjmp/longjmp, so you must either build the library
 with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
 and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
 
-XVII. Common linking failures
+XV. Common linking failures
 
 If your application fails to find libpng or zlib entries while linking:
 
@@ -453,12 +451,13 @@ If your application fails to find libpng or zlib entries while linking:
   If you are using the vstudio project, observe the WARNING in
   project/vstudio/README.txt.
 
-XVIII. Other sources of information about libpng:
+XVI. Other sources of information about libpng:
 
 Further information can be found in the README and libpng-manual.txt
 files, in the individual makefiles, in png.h, and the manual pages
 libpng.3 and png.5.
 
+Copyright (c) 2022 Cosmin Truta
 Copyright (c) 1998-2002,2006-2016 Glenn Randers-Pehrson
 This document is released under the libpng license.
 For conditions of distribution and use, see the disclaimer
diff --git a/src/3rdparty/libpng/LICENSE b/src/3rdparty/libpng/LICENSE
index e0c5b531cf..c8ad24eecf 100644
--- a/src/3rdparty/libpng/LICENSE
+++ b/src/3rdparty/libpng/LICENSE
@@ -4,8 +4,8 @@ COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
 PNG Reference Library License version 2
 ---------------------------------------
 
- * Copyright (c) 1995-2019 The PNG Reference Library Authors.
- * Copyright (c) 2018-2019 Cosmin Truta.
+ * Copyright (c) 1995-2022 The PNG Reference Library Authors.
+ * Copyright (c) 2018-2022 Cosmin Truta.
  * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
  * Copyright (c) 1996-1997 Andreas Dilger.
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
diff --git a/src/3rdparty/libpng/README b/src/3rdparty/libpng/README
index cfc1f0e3dc..e6e72aa547 100644
--- a/src/3rdparty/libpng/README
+++ b/src/3rdparty/libpng/README
@@ -1,12 +1,12 @@
-README for libpng version 1.6.37 - April 14, 2019
-=================================================
+README for libpng version 1.6.38
+================================
 
 See the note about version numbers near the top of png.h.
 See INSTALL for instructions on how to install libpng.
 
 Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
-libpng-*.tar.xz or if you want UNIX-style line endings in the text
-files, or lpng*.7z or lpng*.zip if you want DOS-style line endings.
+libpng-*.tar.xz if you want UNIX-style line endings in the text files,
+or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
 fact that it's the first release fool you.  The libpng library has been
diff --git a/src/3rdparty/libpng/libpng-manual.txt b/src/3rdparty/libpng/libpng-manual.txt
index 5dad92fbf7..19b1e0c356 100644
--- a/src/3rdparty/libpng/libpng-manual.txt
+++ b/src/3rdparty/libpng/libpng-manual.txt
@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- Copyright (c) 2018-2019 Cosmin Truta
+ Copyright (c) 2018-2022 Cosmin Truta
  Copyright (c) 1998-2018 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
@@ -9,9 +9,9 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng version 1.6.36, December 2018, through 1.6.37 - April 2019
+ libpng version 1.6.36, December 2018, through 1.6.38 - September 2022
  Updated and distributed by Cosmin Truta
- Copyright (c) 2018-2019 Cosmin Truta
+ Copyright (c) 2018-2022 Cosmin Truta
 
  libpng versions 0.97, January 1998, through 1.6.35 - July 2018
  Updated and distributed by Glenn Randers-Pehrson
@@ -1792,7 +1792,7 @@ the information.  If, instead, you want to convert the image to an opaque
 version with no alpha channel use png_set_background; see below.
 
 As of libpng version 1.5.2, almost all useful expansions are supported, the
-major ommissions are conversion of grayscale to indexed images (which can be
+major omissions are conversion of grayscale to indexed images (which can be
 done trivially in the application) and conversion of indexed to grayscale (which
 can be done by a trivial manipulation of the palette.)
 
diff --git a/src/3rdparty/libpng/png.c b/src/3rdparty/libpng/png.c
index 757c755f97..fc09564262 100644
--- a/src/3rdparty/libpng/png.c
+++ b/src/3rdparty/libpng/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_37 Your_png_h_is_not_version_1_6_37;
+typedef png_libpng_version_1_6_38 Your_png_h_is_not_version_1_6_38;
 
 #ifdef __GNUC__
 /* The version tests may need to be added to, but the problem warning has
@@ -720,7 +720,7 @@ png_init_io(png_structrp png_ptr, png_FILE_p fp)
  *
  * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the
  * negative integral value is added the result will be an unsigned value
- * correspnding to the 2's complement representation.
+ * corresponding to the 2's complement representation.
  */
 void PNGAPI
 png_save_int_32(png_bytep buf, png_int_32 i)
@@ -815,8 +815,8 @@ png_get_copyright(png_const_structrp png_ptr)
    return PNG_STRING_COPYRIGHT
 #else
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.37" PNG_STRING_NEWLINE \
-      "Copyright (c) 2018-2019 Cosmin Truta" PNG_STRING_NEWLINE \
+      "libpng version 1.6.38" PNG_STRING_NEWLINE \
+      "Copyright (c) 2018-2022 Cosmin Truta" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
       "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
@@ -1843,12 +1843,12 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
 #  ifdef PNG_WARNINGS_SUPPORTED
    else
       {
-         char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114*/
+         char number[PNG_NUMBER_BUFFER_SIZE]; /* +24 = 114 */
 
          pos = png_safecat(message, (sizeof message), pos,
              png_format_number(number, number+(sizeof number),
              PNG_NUMBER_FORMAT_x, value));
-         pos = png_safecat(message, (sizeof message), pos, "h: "); /*+2 = 116*/
+         pos = png_safecat(message, (sizeof message), pos, "h: "); /* +2 = 116 */
       }
 #  endif
    /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
diff --git a/src/3rdparty/libpng/png.h b/src/3rdparty/libpng/png.h
index 139eb0dc0f..5fb494fb1a 100644
--- a/src/3rdparty/libpng/png.h
+++ b/src/3rdparty/libpng/png.h
@@ -1,9 +1,9 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.37 - April 14, 2019
+ * libpng version 1.6.38 - September 14, 2022
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -15,7 +15,7 @@
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
  *   libpng versions 0.97, January 1998, through 1.6.35, July 2018:
  *     Glenn Randers-Pehrson
- *   libpng versions 1.6.36, December 2018, through 1.6.37, April 2019:
+ *   libpng versions 1.6.36, December 2018, through 1.6.38, September 2022:
  *     Cosmin Truta
  *   See also "Contributing Authors", below.
  */
@@ -27,8 +27,8 @@
  * PNG Reference Library License version 2
  * ---------------------------------------
  *
- *  * Copyright (c) 1995-2019 The PNG Reference Library Authors.
- *  * Copyright (c) 2018-2019 Cosmin Truta.
+ *  * Copyright (c) 1995-2022 The PNG Reference Library Authors.
+ *  * Copyright (c) 2018-2022 Cosmin Truta.
  *  * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
  *  * Copyright (c) 1996-1997 Andreas Dilger.
  *  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -239,7 +239,7 @@
  *    ...
  *    1.5.30                  15    10530  15.so.15.30[.0]
  *    ...
- *    1.6.37                  16    10637  16.so.16.37[.0]
+ *    1.6.38                  16    10638  16.so.16.38[.0]
  *
  *    Henceforth the source version will match the shared-library major and
  *    minor numbers; the shared-library major version number will be used for
@@ -278,8 +278,8 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.37"
-#define PNG_HEADER_VERSION_STRING " libpng version 1.6.37 - April 14, 2019\n"
+#define PNG_LIBPNG_VER_STRING "1.6.38"
+#define PNG_HEADER_VERSION_STRING " libpng version 1.6.38 - September 14, 2022\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -287,7 +287,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 37
+#define PNG_LIBPNG_VER_RELEASE 38
 
 /* This should be zero for a public release, or non-zero for a
  * development version.  [Deprecated]
@@ -318,7 +318,7 @@
  * From version 1.0.1 it is:
  * XXYYZZ, where XX=major, YY=minor, ZZ=release
  */
-#define PNG_LIBPNG_VER 10637 /* 1.6.37 */
+#define PNG_LIBPNG_VER 10638 /* 1.6.38 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -428,7 +428,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_37;
+typedef char* png_libpng_version_1_6_38;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -1446,7 +1446,7 @@ PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
  * mainly useful for testing, as the defaults should work with most users.
  * Those users who are tight on memory or want faster performance at the
  * expense of compression can modify them.  See the compression library
- * header file (zlib.h) for an explination of the compression functions.
+ * header file (zlib.h) for an explanation of the compression functions.
  */
 
 /* Set the filtering method(s) used by libpng.  Currently, the only valid
@@ -1501,7 +1501,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
  * shown that zlib compression levels 3-6 usually perform as well as level 9
- * for PNG images, and do considerably fewer caclulations.  In the future,
+ * for PNG images, and do considerably fewer calculations.  In the future,
  * these values may not correspond directly to the zlib compression levels.
  */
 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
diff --git a/src/3rdparty/libpng/pngconf.h b/src/3rdparty/libpng/pngconf.h
index 927a769dbe..89d28f83a0 100644
--- a/src/3rdparty/libpng/pngconf.h
+++ b/src/3rdparty/libpng/pngconf.h
@@ -1,9 +1,9 @@
 
 /* pngconf.h - machine-configurable file for libpng
  *
- * libpng version 1.6.37
+ * libpng version 1.6.38
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -180,8 +180,8 @@
  * compiler-specific macros to the values required to change the calling
  * conventions of the various functions.
  */
-#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
-    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+    defined(__CYGWIN__)
   /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
    * MinGW on any architecture currently supported by Windows.  Also includes
    * Watcom builds but these need special treatment because they are not
diff --git a/src/3rdparty/libpng/pngget.c b/src/3rdparty/libpng/pngget.c
index 5abf1efd9f..e44933c0d2 100644
--- a/src/3rdparty/libpng/pngget.c
+++ b/src/3rdparty/libpng/pngget.c
@@ -1151,7 +1151,7 @@ png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 png_byte PNGAPI
-png_get_rgb_to_gray_status (png_const_structrp png_ptr)
+png_get_rgb_to_gray_status(png_const_structrp png_ptr)
 {
    return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
 }
@@ -1192,27 +1192,27 @@ png_get_compression_buffer_size(png_const_structrp png_ptr)
 /* These functions were added to libpng 1.2.6 and were enabled
  * by default in libpng-1.4.0 */
 png_uint_32 PNGAPI
-png_get_user_width_max (png_const_structrp png_ptr)
+png_get_user_width_max(png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_width_max : 0);
 }
 
 png_uint_32 PNGAPI
-png_get_user_height_max (png_const_structrp png_ptr)
+png_get_user_height_max(png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_height_max : 0);
 }
 
 /* This function was added to libpng 1.4.0 */
 png_uint_32 PNGAPI
-png_get_chunk_cache_max (png_const_structrp png_ptr)
+png_get_chunk_cache_max(png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
 }
 
 /* This function was added to libpng 1.4.1 */
 png_alloc_size_t PNGAPI
-png_get_chunk_malloc_max (png_const_structrp png_ptr)
+png_get_chunk_malloc_max(png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
 }
@@ -1221,13 +1221,13 @@ png_get_chunk_malloc_max (png_const_structrp png_ptr)
 /* These functions were added to libpng 1.4.0 */
 #ifdef PNG_IO_STATE_SUPPORTED
 png_uint_32 PNGAPI
-png_get_io_state (png_const_structrp png_ptr)
+png_get_io_state(png_const_structrp png_ptr)
 {
    return png_ptr->io_state;
 }
 
 png_uint_32 PNGAPI
-png_get_io_chunk_type (png_const_structrp png_ptr)
+png_get_io_chunk_type(png_const_structrp png_ptr)
 {
    return png_ptr->chunk_name;
 }
diff --git a/src/3rdparty/libpng/pnglibconf.h b/src/3rdparty/libpng/pnglibconf.h
index e1e27e957e..89d5b4c8ad 100644
--- a/src/3rdparty/libpng/pnglibconf.h
+++ b/src/3rdparty/libpng/pnglibconf.h
@@ -1,8 +1,8 @@
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.6.37 */
+/* libpng version 1.6.38 */
 
-/* Copyright (c) 2018-2019 Cosmin Truta */
+/* Copyright (c) 2018-2022 Cosmin Truta */
 /* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson */
 
 /* This code is released under the libpng license. */
diff --git a/src/3rdparty/libpng/pngpriv.h b/src/3rdparty/libpng/pngpriv.h
index acfc9cf280..2e426cf47d 100644
--- a/src/3rdparty/libpng/pngpriv.h
+++ b/src/3rdparty/libpng/pngpriv.h
@@ -1,7 +1,7 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -23,12 +23,6 @@
 #ifndef PNGPRIV_H
 #define PNGPRIV_H
 
-#ifdef _MSC_VER
-#  ifndef _CRT_SECURE_NO_DEPRECATE
-#    define _CRT_SECURE_NO_DEPRECATE
-#  endif
-#endif
-
 /* Feature Test Macros.  The following are defined here to ensure that correctly
  * implemented libraries reveal the APIs libpng needs to build and hide those
  * that are not needed and potentially damaging to the compilation.
@@ -180,7 +174,7 @@
 #     else /* !defined __ARM_NEON__ */
          /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
           */
-#        if !defined(__aarch64__)
+#        if !defined(__aarch64__) && !defined(_M_ARM64)
             /* The assembler code currently does not work on ARM64 */
 #          define PNG_ARM_NEON_IMPLEMENTATION 2
 #        endif /* __aarch64__ */
@@ -191,6 +185,8 @@
       /* Use the intrinsics code by default. */
 #     define PNG_ARM_NEON_IMPLEMENTATION 1
 #  endif
+#else /* PNG_ARM_NEON_OPT == 0 */
+#     define PNG_ARM_NEON_IMPLEMENTATION 0
 #endif /* PNG_ARM_NEON_OPT > 0 */
 
 #ifndef PNG_MIPS_MSA_OPT
@@ -269,11 +265,15 @@
 #  ifndef PNG_MIPS_MSA_IMPLEMENTATION
 #     define PNG_MIPS_MSA_IMPLEMENTATION 1
 #  endif
+#else
+#  define PNG_MIPS_MSA_IMPLEMENTATION 0
 #endif /* PNG_MIPS_MSA_OPT > 0 */
 
 #if PNG_POWERPC_VSX_OPT > 0
 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_vsx
 #  define PNG_POWERPC_VSX_IMPLEMENTATION 1
+#else
+#  define PNG_POWERPC_VSX_IMPLEMENTATION 0
 #endif
 
 
@@ -314,11 +314,6 @@
 #  endif
 #endif /* Setting PNG_BUILD_DLL if required */
 
-/* Modfied for usage in Qt: Do not export the libpng APIs */
-#ifdef PNG_BUILD_DLL
-#undef PNG_BUILD_DLL
-#endif
-
 /* See pngconf.h for more details: the builder of the library may set this on
  * the command line to the right thing for the specific compilation system or it
  * may be automagically set above (at present we know of no system where it does
@@ -503,16 +498,7 @@
    static_cast<type>(static_cast<const void*>(value))
 #else
 #  define png_voidcast(type, value) (value)
-#  ifdef _WIN64
-#     ifdef __GNUC__
-         typedef unsigned long long png_ptruint;
-#     else
-         typedef unsigned __int64 png_ptruint;
-#     endif
-#  else
-      typedef unsigned long png_ptruint;
-#  endif
-#  define png_constcast(type, value) ((type)(png_ptruint)(const void*)(value))
+#  define png_constcast(type, value) ((type)(void*)(const void*)(value))
 #  define png_aligncast(type, value) ((void*)(value))
 #  define png_aligncastconst(type, value) ((const void*)(value))
 #endif /* __cplusplus */
@@ -554,9 +540,8 @@
 #  include <alloc.h>
 #endif
 
-#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
-    defined(_WIN32) || defined(__WIN32__)
-#  include <windows.h>  /* defines _WINDOWS_ macro */
+#if defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
+#  include <windows.h>
 #endif
 #endif /* PNG_VERSION_INFO_ONLY */
 
@@ -565,24 +550,20 @@
  * functions that are passed far data must be model-independent.
  */
 
-/* Memory model/platform independent fns */
+/* Platform-independent functions */
 #ifndef PNG_ABORT
-#  if (defined(_WINDOWS_) || defined(_WIN32_WCE))
-#    define PNG_ABORT() ExitProcess(0)
-#  else
-#    define PNG_ABORT() abort()
-#  endif
+#  define PNG_ABORT() abort()
 #endif
 
 /* These macros may need to be architecture dependent. */
-#define PNG_ALIGN_NONE   0 /* do not use data alignment */
-#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
+#define PNG_ALIGN_NONE      0 /* do not use data alignment */
+#define PNG_ALIGN_ALWAYS    1 /* assume unaligned accesses are OK */
 #ifdef offsetof
-#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
+#  define PNG_ALIGN_OFFSET  2 /* use offsetof to determine alignment */
 #else
 #  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
 #endif
-#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
+#define PNG_ALIGN_SIZE      3 /* use sizeof to determine alignment */
 
 #ifndef PNG_ALIGN_TYPE
    /* Default to using aligned access optimizations and requiring alignment to a
@@ -596,26 +577,25 @@
    /* This is used because in some compiler implementations non-aligned
     * structure members are supported, so the offsetof approach below fails.
     * Set PNG_ALIGN_SIZE=0 for compiler combinations where unaligned access
-    * is good for performance.  Do not do this unless you have tested the result
-    * and understand it.
+    * is good for performance.  Do not do this unless you have tested the
+    * result and understand it.
     */
-#  define png_alignof(type) (sizeof (type))
+#  define png_alignof(type) (sizeof(type))
 #else
 #  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
-#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
+#    define png_alignof(type) offsetof(struct{char c; type t;}, t)
 #  else
-#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
-#        define png_alignof(type) (1)
-#     endif
-      /* Else leave png_alignof undefined to prevent use thereof */
+#    if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
+#      define png_alignof(type) 1
+#    endif
+     /* Else leave png_alignof undefined to prevent use thereof */
 #  endif
 #endif
 
-/* This implicitly assumes alignment is always to a power of 2. */
+/* This implicitly assumes alignment is always a multiple of 2. */
 #ifdef png_alignof
-#  define png_isaligned(ptr, type)\
-   (((type)((const char*)ptr-(const char*)0) & \
-   (type)(png_alignof(type)-1)) == 0)
+#  define png_isaligned(ptr, type) \
+   (((type)(size_t)((const void*)(ptr)) & (type)(png_alignof(type)-1)) == 0)
 #else
 #  define png_isaligned(ptr, type) 0
 #endif
diff --git a/src/3rdparty/libpng/pngread.c b/src/3rdparty/libpng/pngread.c
index 8fa7d9f162..5ab9224038 100644
--- a/src/3rdparty/libpng/pngread.c
+++ b/src/3rdparty/libpng/pngread.c
@@ -3452,7 +3452,6 @@ png_image_read_background(png_voidp argument)
 
             for (pass = 0; pass < passes; ++pass)
             {
-               png_bytep row = png_voidcast(png_bytep, display->first_row);
                unsigned int     startx, stepx, stepy;
                png_uint_32      y;
 
@@ -3557,8 +3556,6 @@ png_image_read_background(png_voidp argument)
 
                         inrow += 2; /* gray and alpha channel */
                      }
-
-                     row += display->row_bytes;
                   }
                }
             }
diff --git a/src/3rdparty/libpng/pngrtran.c b/src/3rdparty/libpng/pngrtran.c
index 9a8fad9f4a..238f5afe7e 100644
--- a/src/3rdparty/libpng/pngrtran.c
+++ b/src/3rdparty/libpng/pngrtran.c
@@ -21,7 +21,7 @@
 #ifdef PNG_ARM_NEON_IMPLEMENTATION
 #  if PNG_ARM_NEON_IMPLEMENTATION == 1
 #    define PNG_ARM_NEON_INTRINSICS_AVAILABLE
-#    if defined(_MSC_VER) && defined(_M_ARM64)
+#    if defined(_MSC_VER) && !defined(__clang__) && defined(_M_ARM64)
 #      include <arm64_neon.h>
 #    else
 #      include <arm_neon.h>
diff --git a/src/3rdparty/libpng/pngrutil.c b/src/3rdparty/libpng/pngrutil.c
index 4db3de990b..ca060dd15f 100644
--- a/src/3rdparty/libpng/pngrutil.c
+++ b/src/3rdparty/libpng/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -302,7 +302,6 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
    if (buffer != NULL && new_size > png_ptr->read_buffer_size)
    {
       png_ptr->read_buffer = NULL;
-      png_ptr->read_buffer = NULL;
       png_ptr->read_buffer_size = 0;
       png_free(png_ptr, buffer);
       buffer = NULL;
@@ -2076,14 +2075,17 @@ png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
       png_byte buf[1];
       png_crc_read(png_ptr, buf, 1);
       info_ptr->eXIf_buf[i] = buf[0];
-      if (i == 1 && buf[0] != 'M' && buf[0] != 'I'
-                 && info_ptr->eXIf_buf[0] != buf[0])
+      if (i == 1)
       {
-         png_crc_finish(png_ptr, length);
-         png_chunk_benign_error(png_ptr, "incorrect byte-order specifier");
-         png_free(png_ptr, info_ptr->eXIf_buf);
-         info_ptr->eXIf_buf = NULL;
-         return;
+         if ((buf[0] != 'M' && buf[0] != 'I') ||
+             (info_ptr->eXIf_buf[0] != buf[0]))
+         {
+            png_crc_finish(png_ptr, length - 2);
+            png_chunk_benign_error(png_ptr, "incorrect byte-order specifier");
+            png_free(png_ptr, info_ptr->eXIf_buf);
+            info_ptr->eXIf_buf = NULL;
+            return;
+         }
       }
    }
 
@@ -2124,8 +2126,9 @@ png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 
    num = length / 2 ;
 
-   if (num != (unsigned int) png_ptr->num_palette ||
-       num > (unsigned int) PNG_MAX_PALETTE_LENGTH)
+   if (length != num * 2 ||
+       num != (unsigned int)png_ptr->num_palette ||
+       num > (unsigned int)PNG_MAX_PALETTE_LENGTH)
    {
       png_crc_finish(png_ptr, length);
       png_chunk_benign_error(png_ptr, "invalid");
@@ -4619,14 +4622,13 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
        */
       {
          png_bytep temp = png_ptr->big_row_buf + 32;
-         int extra = (int)((temp - (png_bytep)0) & 0x0f);
+         size_t extra = (size_t)temp & 0x0f;
          png_ptr->row_buf = temp - extra - 1/*filter byte*/;
 
          temp = png_ptr->big_prev_row + 32;
-         extra = (int)((temp - (png_bytep)0) & 0x0f);
+         extra = (size_t)temp & 0x0f;
          png_ptr->prev_row = temp - extra - 1/*filter byte*/;
       }
-
 #else
       /* Use 31 bytes of padding before and 17 bytes after row_buf. */
       png_ptr->row_buf = png_ptr->big_row_buf + 31;
diff --git a/src/3rdparty/libpng/pngset.c b/src/3rdparty/libpng/pngset.c
index ec75dbe369..8c372cf415 100644
--- a/src/3rdparty/libpng/pngset.c
+++ b/src/3rdparty/libpng/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -1019,6 +1019,9 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
           info_ptr->trans_alpha = png_voidcast(png_bytep,
               png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
           memcpy(info_ptr->trans_alpha, trans_alpha, (size_t)num_trans);
+
+          info_ptr->valid |= PNG_INFO_tRNS;
+          info_ptr->free_me |= PNG_FREE_TRNS;
        }
        png_ptr->trans_alpha = info_ptr->trans_alpha;
    }
@@ -1326,7 +1329,7 @@ png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
 png_uint_32 PNGAPI
-png_permit_mng_features (png_structrp png_ptr, png_uint_32 mng_features)
+png_permit_mng_features(png_structrp png_ptr, png_uint_32 mng_features)
 {
    png_debug(1, "in png_permit_mng_features");
 
@@ -1633,7 +1636,7 @@ png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
 /* This function was added to libpng 1.2.6 */
 void PNGAPI
-png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
+png_set_user_limits(png_structrp png_ptr, png_uint_32 user_width_max,
     png_uint_32 user_height_max)
 {
    /* Images with dimensions larger than these limits will be
@@ -1649,7 +1652,7 @@ png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
 
 /* This function was added to libpng 1.4.0 */
 void PNGAPI
-png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
+png_set_chunk_cache_max(png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
 {
    if (png_ptr != NULL)
       png_ptr->user_chunk_cache_max = user_chunk_cache_max;
@@ -1657,7 +1660,7 @@ png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
 
 /* This function was added to libpng 1.4.1 */
 void PNGAPI
-png_set_chunk_malloc_max (png_structrp png_ptr,
+png_set_chunk_malloc_max(png_structrp png_ptr,
     png_alloc_size_t user_chunk_malloc_max)
 {
    if (png_ptr != NULL)
diff --git a/src/3rdparty/libpng/pngstruct.h b/src/3rdparty/libpng/pngstruct.h
index 8bdc7ce46d..e591d94d58 100644
--- a/src/3rdparty/libpng/pngstruct.h
+++ b/src/3rdparty/libpng/pngstruct.h
@@ -1,7 +1,7 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -334,18 +334,8 @@ struct png_struct_def
    size_t current_buffer_size;       /* amount of data now in current_buffer */
    int process_mode;                 /* what push library is currently doing */
    int cur_palette;                  /* current push library palette index */
-
 #endif /* PROGRESSIVE_READ */
 
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* For the Borland special 64K segment handler */
-   png_bytepp offset_table_ptr;
-   png_bytep offset_table;
-   png_uint_16 offset_table_number;
-   png_uint_16 offset_table_count;
-   png_uint_16 offset_table_count_free;
-#endif
-
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
    png_bytep palette_lookup; /* lookup table for quantizing */
    png_bytep quantize_index; /* index translation for palette files */
diff --git a/src/3rdparty/libpng/pngwrite.c b/src/3rdparty/libpng/pngwrite.c
index 59377a4dde..06c45d16ab 100644
--- a/src/3rdparty/libpng/pngwrite.c
+++ b/src/3rdparty/libpng/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Copyright (c) 2018-2019 Cosmin Truta
+ * Copyright (c) 2018-2022 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -489,6 +489,16 @@ png_convert_from_time_t(png_timep ptime, time_t ttime)
    png_debug(1, "in png_convert_from_time_t");
 
    tbuf = gmtime(&ttime);
+   if (tbuf == NULL)
+   {
+      /* TODO: add a safe function which takes a png_ptr argument and raises
+       * a png_error if the ttime argument is invalid and the call to gmtime
+       * fails as a consequence.
+       */
+      memset(ptime, 0, sizeof(*ptime));
+      return;
+   }
+
    png_convert_from_struct_tm(ptime, tbuf);
 }
 #endif
diff --git a/src/3rdparty/libpng/qt_attribution.json b/src/3rdparty/libpng/qt_attribution.json
index 612aa67791..4867220ca3 100644
--- a/src/3rdparty/libpng/qt_attribution.json
+++ b/src/3rdparty/libpng/qt_attribution.json
@@ -6,21 +6,23 @@
 
     "Description": "libpng is the official PNG reference library.",
     "Homepage": "http://www.libpng.org/pub/png/libpng.html",
-    "Version": "1.6.37",
+    "Version": "1.6.38",
     "License": "libpng License and PNG Reference Library version 2",
     "LicenseId": "Libpng AND libpng-2.0",
     "LicenseFile": "LICENSE",
-    "Copyright": "Copyright (c) 1998-2018 Glenn Randers-Pehrson
+    "Copyright": "Copyright (c) 1995-2022 The PNG Reference Library Authors
+Copyright (c) 2000-2022 Cosmin Truta
+Copyright (c) 1998-2018 Glenn Randers-Pehrson
+Copyright (c) 1996-1997 Andreas Dilger
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 Copyright (c) 2000-2017 Simon-Pierre Cadieux
 Copyright (c) 2000-2017 Eric S. Raymond
 Copyright (c) 2000-2017 Mans Rullgard
-Copyright (c) 2000-2019 Cosmin Truta
 Copyright (c) 2000-2017 Gilles Vollant
 Copyright (c) 2000-2017 James Yu
 Copyright (c) 2000-2017 Mandar Sahastrabuddhe
 Copyright (c) 1998-2000 Tom Lane
 Copyright (c) 1998-2000 Willem van Schaik
-Copyright (c) 1996-1997 Andreas Dilger
 Copyright (c) 1996-1997 John Bowler
 Copyright (c) 1996-1997 Kevin Bracey
 Copyright (c) 1996-1997 Sam Bushell
@@ -29,6 +31,5 @@ Copyright (c) 1996-1997 Greg Roelofs
 Copyright (c) 1996-1997 Tom Tanner
 Copyright (c) 1995-1996 Dave Martindale
 Copyright (c) 1995-1996 Paul Schmidt
-Copyright (c) 1995-1996 Tim Wegner
-Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc."
+Copyright (c) 1995-1996 Tim Wegner"
 }
diff --git a/src/3rdparty/libpng/qtpatches.diff b/src/3rdparty/libpng/qtpatches.diff
deleted file mode 100644
index b2bdb1475d..0000000000
--- a/src/3rdparty/libpng/qtpatches.diff
+++ /dev/null
@@ -1,62 +0,0 @@
-diff --git a/src/3rdparty/libpng/pngpriv.h b/src/3rdparty/libpng/pngpriv.h
-index 583c26f9bd..2ab9b70d73 100644
---- a/src/3rdparty/libpng/pngpriv.h
-+++ b/src/3rdparty/libpng/pngpriv.h
-@@ -23,6 +23,12 @@
- #ifndef PNGPRIV_H
- #define PNGPRIV_H
- 
-+#ifdef _MSC_VER
-+#  ifndef _CRT_SECURE_NO_DEPRECATE
-+#    define _CRT_SECURE_NO_DEPRECATE
-+#  endif
-+#endif
-+
- /* Feature Test Macros.  The following are defined here to ensure that correctly
-  * implemented libraries reveal the APIs libpng needs to build and hide those
-  * that are not needed and potentially damaging to the compilation.
-@@ -308,6 +314,11 @@
- #  endif
- #endif /* Setting PNG_BUILD_DLL if required */
- 
-+/* Modfied for usage in Qt: Do not export the libpng APIs */
-+#ifdef PNG_BUILD_DLL
-+#undef PNG_BUILD_DLL
-+#endif
-+
- /* See pngconf.h for more details: the builder of the library may set this on
-  * the command line to the right thing for the specific compilation system or it
-  * may be automagically set above (at present we know of no system where it does
-@@ -546,6 +557,9 @@
- #if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \
-     defined(_WIN32) || defined(__WIN32__)
- #  include <windows.h>  /* defines _WINDOWS_ macro */
- #endif
- #endif /* PNG_VERSION_INFO_ONLY */
- 
-@@ -556,7 +570,7 @@
- 
- /* Memory model/platform independent fns */
- #ifndef PNG_ABORT
--#  ifdef _WINDOWS_
-+#  if (defined(_WINDOWS_) || defined(_WIN32_WCE))
- #    define PNG_ABORT() ExitProcess(0)
- #  else
- #    define PNG_ABORT() abort()
-diff --git a/src/3rdparty/libpng/pngrutil.c b/src/3rdparty/libpng/pngrutil.c
-index d5fa08c397..4db3de990b 100644
---- a/src/3rdparty/libpng/pngrutil.c
-+++ b/src/3rdparty/libpng/pngrutil.c
-@@ -2087,10 +2087,8 @@ png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
-       }
-    }
- 
--   if (png_crc_finish(png_ptr, 0) != 0)
--      return;
--
--   png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf);
-+   if (png_crc_finish(png_ptr, 0) == 0)
-+      png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf);
- 
-    png_free(png_ptr, info_ptr->eXIf_buf);
-    info_ptr->eXIf_buf = NULL;