Update bundled libpng to version 1.6.43

[ChangeLog][Third-Party Code] libpng was updated to version 1.6.43

Pick-to: 6.7 6.6 6.5 6.2 5.15
Fixes: QTBUG-122989
Change-Id: Id439e64010bc3f6752f5589d663827a91f009173
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

12 files changed, 133 insertions, 108 deletions

diff --git a/src/3rdparty/libpng/ANNOUNCE b/src/3rdparty/libpng/ANNOUNCE
index 44d6722d05..bc147adb78 100644
--- a/src/3rdparty/libpng/ANNOUNCE
+++ b/src/3rdparty/libpng/ANNOUNCE
@@ -1,5 +1,5 @@
-libpng 1.6.42 - January 29, 2024
-================================
+libpng 1.6.43 - February 23, 2024
+=================================
 
 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-1.6.42.tar.xz (LZMA-compressed, recommended)
- * libpng-1.6.42.tar.gz (deflate-compressed)
+ * libpng-1.6.43.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.43.tar.gz (deflate-compressed)
 
 Source files with CRLF line endings (for Windows):
 
- * lpng1642.7z (LZMA-compressed, recommended)
- * lpng1642.zip (deflate-compressed)
+ * lpng1643.7z (LZMA-compressed, recommended)
+ * lpng1643.zip (deflate-compressed)
 
 Other information:
 
@@ -25,47 +25,36 @@ Other information:
  * TRADEMARK.md
 
 
-Changes from version 1.6.41 to version 1.6.42
+Changes from version 1.6.42 to version 1.6.43
 ---------------------------------------------
 
- * Fixed the implementation of the macro function `png_check_sig`.
-   This was an API regression, introduced in libpng-1.6.41.
-   (Reported by Matthieu Darbois)
-
-
-Changes from version 1.6.40 to version 1.6.41
----------------------------------------------
-
- * Added SIMD-optimized code for the Loongarch LSX hardware.
-   (Contributed by GuXiWei, JinBo and ZhangLixia)
- * Fixed the run-time discovery of MIPS MSA hardware.
-   (Contributed by Sui Jingfeng)
- * Fixed an off-by-one error in the function `png_do_check_palette_indexes`,
-   which failed to recognize errors that might have existed in the first
-   column of a broken palette-encoded image. This was a benign regression
-   accidentally introduced in libpng-1.6.33. No pixel was harmed.
-   (Contributed by Adam Richter; reviewed by John Bowler)
- * Fixed, improved and modernized the contrib/pngminus programs, i.e.,
-   png2pnm.c and pnm2png.c
- * Removed old and peculiar portability hacks that were meant to silence
-   warnings issued by gcc version 7.1 alone.
+ * Fixed the row width check in png_check_IHDR().
+   This corrected a bug that was specific to the 16-bit platforms,
+   and removed a spurious compiler warning from the 64-bit builds.
+   (Reported by Jacek Caban; fixed by John Bowler)
+ * Added eXIf chunk support to the push-mode reader in pngpread.c.
+   (Contributed by Chris Blume)
+ * Added contrib/pngexif for the benefit of the users who would like
+   to inspect the content of eXIf chunks.
+ * Added contrib/conftest/basic.dfa, a basic build-time configuration.
    (Contributed by John Bowler)
- * Fixed and modernized the CMake file, and raised the minimum required
-   CMake version from 3.1 to 3.6.
-   (Contributed by Clinton Ingram, Timothy Lyanguzov, Tyler Kropp, et al.)
- * Allowed the configure script to disable the building of auxiliary tools
-   and tests, thus catching up with the CMake file.
-   (Contributed by Carlo Bramini)
- * Fixed a build issue on Mac.
-   (Contributed by Zixu Wang)
- * Moved the Autoconf macro files to scripts/autoconf.
- * Moved the CMake files (except for the main CMakeLists.txt) to
-   scripts/cmake and moved the list of their contributing authors to
-   scripts/cmake/AUTHORS.md
- * Updated the CI configurations and scripts.
- * Relicensed the CI scripts to the MIT License.
- * Improved the test coverage.
+ * Fixed a preprocessor condition in pngread.c that broke build-time
+   configurations like contrib/conftest/pngcp.dfa.
    (Contributed by John Bowler)
+ * Added CMake build support for LoongArch LSX.
+   (Contributed by GuXiWei)
+ * Fixed a CMake build error that occurred under a peculiar state of the
+   dependency tree. This was a regression introduced in libpng-1.6.41.
+   (Contributed by Dan Rosser)
+ * Marked the installed libpng headers as system headers in CMake.
+   (Contributed by Benjamin Buch)
+ * Updated the build support for RISCOS.
+   (Contributed by Cameron Cawley)
+ * Updated the makefiles to allow cross-platform builds to initialize
+   conventional make variables like AR and ARFLAGS.
+ * Added various improvements to the CI scripts in areas like version
+   consistency verification and text linting.
+ * Added version consistency verification to pngtest.c also.
 
 
 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 137761a815..441b57ecf1 100644
--- a/src/3rdparty/libpng/CHANGES
+++ b/src/3rdparty/libpng/CHANGES
@@ -6130,7 +6130,7 @@ Version 1.6.40 [June 21, 2023]
   Cleaned up the code, the build scripts, and the documentation.
 
 Version 1.6.41 [January 24, 2024]
-  Added SIMD-optimized code for the Loongarch LSX hardware.
+  Added SIMD-optimized code for the LoongArch LSX hardware.
     (Contributed by GuXiWei, JinBo and ZhangLixia)
   Fixed the run-time discovery of MIPS MSA hardware.
     (Contributed by Sui Jingfeng)
@@ -6165,6 +6165,36 @@ Version 1.6.42 [January 29, 2024]
   Fixed the implementation of the macro function png_check_sig().
     This was an API regression, introduced in libpng-1.6.41.
     (Reported by Matthieu Darbois)
+  Fixed and updated the libpng manual.
+
+Version 1.6.43 [February 23, 2024]
+  Fixed the row width check in png_check_IHDR().
+    This corrected a bug that was specific to the 16-bit platforms,
+    and removed a spurious compiler warning from the 64-bit builds.
+    (Reported by Jacek Caban; fixed by John Bowler)
+  Added eXIf chunk support to the push-mode reader in pngpread.c.
+    (Contributed by Chris Blume)
+  Added contrib/pngexif for the benefit of the users who would like
+    to inspect the content of eXIf chunks.
+  Added contrib/conftest/basic.dfa, a basic build-time configuration.
+    (Contributed by John Bowler)
+  Fixed a preprocessor condition in pngread.c that broke build-time
+    configurations like contrib/conftest/pngcp.dfa.
+    (Contributed by John Bowler)
+  Added CMake build support for LoongArch LSX.
+    (Contributed by GuXiWei)
+  Fixed a CMake build error that occurred under a peculiar state of the
+    dependency tree. This was a regression introduced in libpng-1.6.41.
+    (Contributed by Dan Rosser)
+  Marked the installed libpng headers as system headers in CMake.
+    (Contributed by Benjamin Buch)
+  Updated the build support for RISCOS.
+    (Contributed by Cameron Cawley)
+  Updated the makefiles to allow cross-platform builds to initialize
+    conventional make variables like AR and ARFLAGS.
+  Added various improvements to the CI scripts in areas like version
+    consistency verification and text linting.
+  Added version consistency verification to pngtest.c also.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
 Subscription is required; visit
diff --git a/src/3rdparty/libpng/README b/src/3rdparty/libpng/README
index 0bf27bcfe6..a6ca3ae9f9 100644
--- a/src/3rdparty/libpng/README
+++ b/src/3rdparty/libpng/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.42
+README for libpng version 1.6.43
 ================================
 
 See the note about version numbers near the top of `png.h`.
@@ -142,10 +142,11 @@ Files included in this distribution
     pngwrite.c    =>  High-level write functions
     pngwtran.c    =>  Write data transformations
     pngwutil.c    =>  Write utility functions
-    arm/          =>  Optimized code for the ARM platform
-    intel/        =>  Optimized code for the INTEL-SSE2 platform
-    mips/         =>  Optimized code for the MIPS platform
-    powerpc/      =>  Optimized code for the PowerPC platform
+    arm/          =>  Optimized code for ARM Neon
+    intel/        =>  Optimized code for INTEL SSE2
+    loongarch/    =>  Optimized code for LoongArch LSX
+    mips/         =>  Optimized code for MIPS MSA and MIPS MMI
+    powerpc/      =>  Optimized code for PowerPC VSX
     ci/           =>  Scripts for continuous integration
     contrib/      =>  External contributions
         arm-neon/     =>  Optimized code for the ARM-NEON platform
@@ -158,6 +159,7 @@ Files included in this distribution
         libtests/     =>  Test programs
         oss-fuzz/     =>  Files used by the OSS-Fuzz project for fuzz-testing
                           libpng
+        pngexif/      =>  Program to inspect the EXIF information in PNG files
         pngminim/     =>  Minimal decoder, encoder, and progressive decoder
                           programs demonstrating the use of pngusr.dfa
         pngminus/     =>  Simple pnm2png and png2pnm programs
diff --git a/src/3rdparty/libpng/libpng-manual.txt b/src/3rdparty/libpng/libpng-manual.txt
index eb24ef4831..7988057599 100644
--- a/src/3rdparty/libpng/libpng-manual.txt
+++ b/src/3rdparty/libpng/libpng-manual.txt
@@ -9,7 +9,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng version 1.6.36, December 2018, through 1.6.42 - January 2024
+ libpng version 1.6.36, December 2018, through 1.6.43 - February 2024
  Updated and distributed by Cosmin Truta
  Copyright (c) 2018-2024 Cosmin Truta
 
@@ -1178,11 +1178,11 @@ where row_pointers is an array of pointers to the pixel data for each row:
 If you know your image size and pixel size ahead of time, you can allocate
 row_pointers prior to calling png_read_png() with
 
-   if (height > PNG_UINT_32_MAX/(sizeof (png_byte)))
+   if (height > PNG_UINT_32_MAX / (sizeof (png_bytep)))
       png_error(png_ptr,
           "Image is too tall to process in memory");
 
-   if (width > PNG_UINT_32_MAX/pixel_size)
+   if (width > PNG_UINT_32_MAX / pixel_size)
       png_error(png_ptr,
           "Image is too wide to process in memory");
 
diff --git a/src/3rdparty/libpng/png.c b/src/3rdparty/libpng/png.c
index cf9f361070..9ed3157009 100644
--- a/src/3rdparty/libpng/png.c
+++ b/src/3rdparty/libpng/png.c
@@ -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_42 Your_png_h_is_not_version_1_6_42;
+typedef png_libpng_version_1_6_43 Your_png_h_is_not_version_1_6_43;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -794,7 +794,7 @@ png_get_copyright(png_const_structrp png_ptr)
    return PNG_STRING_COPYRIGHT
 #else
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.42" PNG_STRING_NEWLINE \
+      "libpng version 1.6.43" PNG_STRING_NEWLINE \
       "Copyright (c) 2018-2024 Cosmin Truta" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
@@ -1821,14 +1821,14 @@ 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,
+          png_format_number(number, number+(sizeof number),
+          PNG_NUMBER_FORMAT_x, value));
+      pos = png_safecat(message, (sizeof message), pos, "h: "); /* +2 = 116 */
+   }
 #  endif
    /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
    pos = png_safecat(message, (sizeof message), pos, reason);
@@ -2511,17 +2511,6 @@ png_colorspace_set_rgb_coefficients(png_structrp png_ptr)
 
 #endif /* COLORSPACE */
 
-#ifdef __GNUC__
-/* This exists solely to work round a warning from GNU C. */
-static int /* PRIVATE */
-png_gt(size_t a, size_t b)
-{
-   return a > b;
-}
-#else
-#   define png_gt(a,b) ((a) > (b))
-#endif
-
 void /* PRIVATE */
 png_check_IHDR(png_const_structrp png_ptr,
     png_uint_32 width, png_uint_32 height, int bit_depth,
@@ -2543,8 +2532,16 @@ png_check_IHDR(png_const_structrp png_ptr,
       error = 1;
    }
 
-   if (png_gt(((width + 7) & (~7U)),
-       ((PNG_SIZE_MAX
+   /* The bit mask on the first line below must be at least as big as a
+    * png_uint_32.  "~7U" is not adequate on 16-bit systems because it will
+    * be an unsigned 16-bit value.  Casting to (png_alloc_size_t) makes the
+    * type of the result at least as bit (in bits) as the RHS of the > operator
+    * which also avoids a common warning on 64-bit systems that the comparison
+    * of (png_uint_32) against the constant value on the RHS will always be
+    * false.
+    */
+   if (((width + 7) & ~(png_alloc_size_t)7) >
+       (((PNG_SIZE_MAX
            - 48        /* big_row_buf hack */
            - 1)        /* filter byte */
            / 8)        /* 8-byte RGBA pixels */
diff --git a/src/3rdparty/libpng/png.h b/src/3rdparty/libpng/png.h
index f537c5bb08..83d3903126 100644
--- a/src/3rdparty/libpng/png.h
+++ b/src/3rdparty/libpng/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.42
+ * libpng version 1.6.43
  *
  * Copyright (c) 2018-2024 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
@@ -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 1.6.42, January 2024:
+ *   libpng versions 1.6.36, December 2018, through 1.6.43, February 2024:
  *     Cosmin Truta
  *   See also "Contributing Authors", below.
  */
@@ -239,7 +239,7 @@
  *    ...
  *    1.5.30                  15    10530  15.so.15.30[.0]
  *    ...
- *    1.6.42                  16    10641  16.so.16.41[.0]
+ *    1.6.43                  16    10643  16.so.16.43[.0]
  *
  *    Henceforth the source version will match the shared-library major and
  *    minor numbers; the shared-library major version number will be used for
@@ -255,9 +255,6 @@
  *    to the info_ptr or png_ptr members through png.h, and the compiled
  *    application is loaded with a different version of the library.
  *
- *    DLLNUM will change each time there are forward or backward changes
- *    in binary compatibility (e.g., when a new feature is added).
- *
  * See libpng.txt or libpng.3 for more information.  The PNG specification
  * is available as a W3C Recommendation and as an ISO/IEC Standard; see
  * <https://www.w3.org/TR/2003/REC-PNG-20031110/>
@@ -278,19 +275,21 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.42"
+#define PNG_LIBPNG_VER_STRING "1.6.43"
 #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
 
-#define PNG_LIBPNG_VER_SONUM   16
-#define PNG_LIBPNG_VER_DLLNUM  16
+/* The versions of shared library builds should stay in sync, going forward */
+#define PNG_LIBPNG_VER_SHAREDLIB 16
+#define PNG_LIBPNG_VER_SONUM     PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
+#define PNG_LIBPNG_VER_DLLNUM    PNG_LIBPNG_VER_SHAREDLIB /* [Deprecated] */
 
 /* 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 41
+#define PNG_LIBPNG_VER_RELEASE 43
 
 /* This should be zero for a public release, or non-zero for a
- * development version.  [Deprecated]
+ * development version.
  */
 #define PNG_LIBPNG_VER_BUILD  0
 
@@ -318,7 +317,7 @@
  * From version 1.0.1 it is:
  * XXYYZZ, where XX=major, YY=minor, ZZ=release
  */
-#define PNG_LIBPNG_VER 10641 /* 1.6.42 */
+#define PNG_LIBPNG_VER 10643 /* 1.6.43 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -428,7 +427,7 @@ 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_42;
+typedef char* png_libpng_version_1_6_43;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
diff --git a/src/3rdparty/libpng/pngconf.h b/src/3rdparty/libpng/pngconf.h
index 99851f4f9c..000d7b1a8a 100644
--- a/src/3rdparty/libpng/pngconf.h
+++ b/src/3rdparty/libpng/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine-configurable file for libpng
  *
- * libpng version 1.6.42
+ * libpng version 1.6.43
  *
  * Copyright (c) 2018-2024 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2016,2018 Glenn Randers-Pehrson
diff --git a/src/3rdparty/libpng/pnglibconf.h b/src/3rdparty/libpng/pnglibconf.h
index 330453c139..83f09fbe77 100644
--- a/src/3rdparty/libpng/pnglibconf.h
+++ b/src/3rdparty/libpng/pnglibconf.h
@@ -1,6 +1,6 @@
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.6.42 */
+/* libpng version 1.6.43 */
 
 /* Copyright (c) 2018-2024 Cosmin Truta */
 /* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson */
diff --git a/src/3rdparty/libpng/pngpread.c b/src/3rdparty/libpng/pngpread.c
index be640f77a9..ffab19c08c 100644
--- a/src/3rdparty/libpng/pngpread.c
+++ b/src/3rdparty/libpng/pngpread.c
@@ -295,6 +295,14 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
    }
 
 #endif
+#ifdef PNG_READ_eXIf_SUPPORTED
+   else if (png_ptr->chunk_name == png_eXIf)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_eXIf(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
 #ifdef PNG_READ_sRGB_SUPPORTED
    else if (chunk_name == png_sRGB)
    {
diff --git a/src/3rdparty/libpng/pngread.c b/src/3rdparty/libpng/pngread.c
index 008a41856b..07a39df6e2 100644
--- a/src/3rdparty/libpng/pngread.c
+++ b/src/3rdparty/libpng/pngread.c
@@ -568,7 +568,11 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
 #endif
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
-   if (png_ptr->transformations || png_ptr->num_palette_max >= 0)
+   if (png_ptr->transformations
+#     ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+         || png_ptr->num_palette_max >= 0
+#     endif
+      )
       png_do_read_transformations(png_ptr, &row_info);
 #endif
 
diff --git a/src/3rdparty/libpng/pngrtran.c b/src/3rdparty/libpng/pngrtran.c
index 16474741aa..1526123e02 100644
--- a/src/3rdparty/libpng/pngrtran.c
+++ b/src/3rdparty/libpng/pngrtran.c
@@ -297,14 +297,13 @@ png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
 
    output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
 
-   /* Validate the value to ensure it is in a reasonable range. The value
+   /* Validate the value to ensure it is in a reasonable range.  The value
     * is expected to be 1 or greater, but this range test allows for some
-    * viewing correction values.  The intent is to weed out users of this API
-    * who use the inverse of the gamma value accidentally!  Since some of these
-    * values are reasonable this may have to be changed:
+    * viewing correction values.  The intent is to weed out the API users
+    * who might use the inverse of the gamma value accidentally!
     *
-    * 1.6.x: changed from 0.07..3 to 0.01..100 (to accommodate the optimal 16-bit
-    * gamma of 36, and its reciprocal.)
+    * In libpng 1.6.0, we changed from 0.07..3 to 0.01..100, to accommodate
+    * the optimal 16-bit gamma of 36 and its reciprocal.
     */
    if (output_gamma < 1000 || output_gamma > 10000000)
       png_error(png_ptr, "output gamma out of expected range");
@@ -441,7 +440,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
       int i;
 
       png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
-          (png_alloc_size_t)((png_uint_32)num_palette * (sizeof (png_byte))));
+          (png_alloc_size_t)num_palette);
       for (i = 0; i < num_palette; i++)
          png_ptr->quantize_index[i] = (png_byte)i;
    }
@@ -458,7 +457,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
 
          /* Initialize an array to sort colors */
          png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
-             (png_alloc_size_t)((png_uint_32)num_palette * (sizeof (png_byte))));
+             (png_alloc_size_t)num_palette);
 
          /* Initialize the quantize_sort array */
          for (i = 0; i < num_palette; i++)
@@ -592,11 +591,9 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
 
          /* Initialize palette index arrays */
          png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
-             (png_alloc_size_t)((png_uint_32)num_palette *
-             (sizeof (png_byte))));
+             (png_alloc_size_t)num_palette);
          png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
-             (png_alloc_size_t)((png_uint_32)num_palette *
-             (sizeof (png_byte))));
+             (png_alloc_size_t)num_palette);
 
          /* Initialize the sort array */
          for (i = 0; i < num_palette; i++)
@@ -761,12 +758,11 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
       size_t num_entries = ((size_t)1 << total_bits);
 
       png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
-          (png_alloc_size_t)(num_entries * (sizeof (png_byte))));
+          (png_alloc_size_t)(num_entries));
 
-      distance = (png_bytep)png_malloc(png_ptr, (png_alloc_size_t)(num_entries *
-          (sizeof (png_byte))));
+      distance = (png_bytep)png_malloc(png_ptr, (png_alloc_size_t)num_entries);
 
-      memset(distance, 0xff, num_entries * (sizeof (png_byte)));
+      memset(distance, 0xff, num_entries);
 
       for (i = 0; i < num_palette; i++)
       {
diff --git a/src/3rdparty/libpng/qt_attribution.json b/src/3rdparty/libpng/qt_attribution.json
index 3268d74d6e..d9621193a3 100644
--- a/src/3rdparty/libpng/qt_attribution.json
+++ b/src/3rdparty/libpng/qt_attribution.json
@@ -7,8 +7,8 @@
 
     "Description": "libpng is the official PNG reference library.",
     "Homepage": "http://www.libpng.org/pub/png/libpng.html",
-    "Version": "1.6.42",
-    "DownloadLocation": "https://download.sourceforge.net/libpng/libpng-1.6.42.tar.xz",
+    "Version": "1.6.43",
+    "DownloadLocation": "https://download.sourceforge.net/libpng/libpng-1.6.43.tar.xz",
 
     "License": "libpng License and PNG Reference Library version 2",
     "LicenseId": "Libpng AND libpng-2.0",