Update bundled libpng to version 1.6.42

[ChangeLog][Third-Party Code] libpng was updated to version 1.6.42

Change-Id: Ie41c2df610fcd456af2bc4dee05dde90c426602b
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit a046bc19e451f6f2e42ac1fcddaf5ef3efc81f0d)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit cd59980f726b5254bd56197acc6f0cbe6d5f1f46)
(cherry picked from commit 85ac5cb9796f40cd01cf585978a7ad54cc75f23d)

10 files changed, 105 insertions, 99 deletions

diff --git a/src/3rdparty/libpng/ANNOUNCE b/src/3rdparty/libpng/ANNOUNCE
index 800446b059..44d6722d05 100644
--- a/src/3rdparty/libpng/ANNOUNCE
+++ b/src/3rdparty/libpng/ANNOUNCE
@@ -1,4 +1,4 @@
-libpng 1.6.41 - January 24, 2024
+libpng 1.6.42 - January 29, 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-1.6.41.tar.xz (LZMA-compressed, recommended)
- * libpng-1.6.41.tar.gz (deflate-compressed)
+ * libpng-1.6.42.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.42.tar.gz (deflate-compressed)
 
 Source files with CRLF line endings (for Windows):
 
- * lpng1641.7z (LZMA-compressed, recommended)
- * lpng1641.zip (deflate-compressed)
+ * lpng1642.7z (LZMA-compressed, recommended)
+ * lpng1642.zip (deflate-compressed)
 
 Other information:
 
@@ -25,6 +25,14 @@ Other information:
  * TRADEMARK.md
 
 
+Changes from version 1.6.41 to version 1.6.42
+---------------------------------------------
+
+ * 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
 ---------------------------------------------
 
diff --git a/src/3rdparty/libpng/CHANGES b/src/3rdparty/libpng/CHANGES
index 2d9a57e439..137761a815 100644
--- a/src/3rdparty/libpng/CHANGES
+++ b/src/3rdparty/libpng/CHANGES
@@ -6134,7 +6134,7 @@ Version 1.6.41 [January 24, 2024]
     (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`,
+  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.
@@ -6161,6 +6161,11 @@ Version 1.6.41 [January 24, 2024]
   Improved the test coverage.
     (Contributed by John Bowler)
 
+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)
+
 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/README b/src/3rdparty/libpng/README
index 1f51a808f7..0bf27bcfe6 100644
--- a/src/3rdparty/libpng/README
+++ b/src/3rdparty/libpng/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.41
+README for libpng version 1.6.42
 ================================
 
 See the note about version numbers near the top of `png.h`.
diff --git a/src/3rdparty/libpng/libpng-manual.txt b/src/3rdparty/libpng/libpng-manual.txt
index dbb60af61d..eb24ef4831 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 1.6.41 - January 2024
+ libpng version 1.6.36, December 2018, through 1.6.42 - January 2024
  Updated and distributed by Cosmin Truta
  Copyright (c) 2018-2024 Cosmin Truta
 
@@ -357,7 +357,7 @@ Customizing libpng.
        return ERROR;
     }
 
-    is_png = !png_sig_cmp(header, 0, number);
+    is_png = (png_sig_cmp(header, 0, number) == 0);
     if (!is_png)
     {
        return NOT_PNG;
@@ -385,8 +385,7 @@ create the structure, so your application should check for that.
 
     if (!info_ptr)
     {
-       png_destroy_read_struct(&png_ptr,
-           (png_infopp)NULL, (png_infopp)NULL);
+       png_destroy_read_struct(&png_ptr, NULL, NULL);
        return ERROR;
     }
 
@@ -419,14 +418,13 @@ free any memory.
 
     if (setjmp(png_jmpbuf(png_ptr)))
     {
-       png_destroy_read_struct(&png_ptr, &info_ptr,
-           &end_info);
+       png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
        fclose(fp);
        return ERROR;
     }
 
-Pass (png_infopp)NULL instead of &end_info if you didn't create
-an end_info structure.
+Pass NULL instead of &end_info if you didn't create an end_info
+structure.
 
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
@@ -496,7 +494,7 @@ You can set up a callback function to handle any unknown chunks in the
 input stream. You must supply the function
 
     read_chunk_callback(png_structp png_ptr,
-         png_unknown_chunkp chunk);
+         png_unknown_chunkp chunk)
     {
        /* The unknown chunk structure contains your
           chunk data, along with similar data for any other
@@ -547,9 +545,9 @@ a progress meter or the like.  It's demonstrated in pngtest.c.
 You must supply a function
 
     void read_row_callback(png_structp png_ptr,
-       png_uint_32 row, int pass);
+       png_uint_32 row, int pass)
     {
-      /* put your code here */
+       /* put your code here */
     }
 
 (You can give it another name that you like instead of "read_row_callback")
@@ -1181,21 +1179,21 @@ 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)))
-      png_error (png_ptr,
+      png_error(png_ptr,
           "Image is too tall to process in memory");
 
    if (width > PNG_UINT_32_MAX/pixel_size)
-      png_error (png_ptr,
+      png_error(png_ptr,
           "Image is too wide to process in memory");
 
    row_pointers = png_malloc(png_ptr,
        height*(sizeof (png_bytep)));
 
-   for (int i=0; i<height, i++)
-      row_pointers[i]=NULL;  /* security precaution */
+   for (int i = 0; i < height, i++)
+      row_pointers[i] = NULL;  /* security precaution */
 
-   for (int i=0; i<height, i++)
-      row_pointers[i]=png_malloc(png_ptr,
+   for (int i = 0; i < height, i++)
+      row_pointers[i] = png_malloc(png_ptr,
           width*pixel_size);
 
    png_set_rows(png_ptr, info_ptr, &row_pointers);
@@ -1205,14 +1203,14 @@ row_pointers[i] to point into the proper places in your block, but first
 be sure that your platform is able to allocate such a large buffer:
 
    /* Guard against integer overflow */
-   if (height > PNG_SIZE_MAX/(width*pixel_size)) {
-        png_error(png_ptr,"image_data buffer would be too large");
-   }
+   if (height > PNG_SIZE_MAX/(width*pixel_size))
+      png_error(png_ptr, "image_data buffer would be too large");
 
-   png_bytep buffer=png_malloc(png_ptr,height*width*pixel_size);
+   png_bytep buffer = png_malloc(png_ptr,
+      height*width*pixel_size);
 
-   for (int i=0; i<height, i++)
-      row_pointers[i]=buffer+i*width*pixel_size;
+   for (int i = 0; i < height, i++)
+      row_pointers[i] = buffer + i*width*pixel_size;
 
    png_set_rows(png_ptr, info_ptr, &row_pointers);
 
@@ -1465,25 +1463,24 @@ png_set_rgb_to_gray()).
                      non-paletted images (PNG_INFO_tRNS)
 
     png_get_eXIf_1(png_ptr, info_ptr, &num_exif, &exif);
-                     (PNG_INFO_eXIf)
 
     exif           - Exif profile (array of png_byte)
+                     (PNG_INFO_eXIf)
 
     png_get_hIST(png_ptr, info_ptr, &hist);
-                     (PNG_INFO_hIST)
 
     hist           - histogram of palette (array of
-                     png_uint_16)
+                     png_uint_16) (PNG_INFO_hIST)
 
     png_get_tIME(png_ptr, info_ptr, &mod_time);
 
     mod_time       - time image was last modified
-                    (PNG_VALID_tIME)
+                     (PNG_INFO_tIME)
 
     png_get_bKGD(png_ptr, info_ptr, &background);
 
     background     - background color (of type
-                     png_color_16p) (PNG_VALID_bKGD)
+                     png_color_16p) (PNG_INFO_bKGD)
                      valid 16-bit red, green and blue
                      values, regardless of color_type
 
@@ -1743,13 +1740,13 @@ grayscale images with bit depths of 2 or 4 or if there is a multiple-image
 viewing application that wishes to treat all images in the same way.
 
     if (color_type == PNG_COLOR_TYPE_PALETTE)
-        png_set_palette_to_rgb(png_ptr);
+       png_set_palette_to_rgb(png_ptr);
 
-    if (png_get_valid(png_ptr, info_ptr,
-        PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+       png_set_tRNS_to_alpha(png_ptr);
 
-    if (color_type == PNG_COLOR_TYPE_GRAY &&
-        bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+       png_set_expand_gray_1_2_4_to_8(png_ptr);
 
 The first two functions are actually aliases for png_set_expand(), added
 in libpng version 1.0.4, with the function names expanded to improve code
@@ -1764,18 +1761,20 @@ png_set_expand(); however, the resultant channels have 16 bits rather than 8.
 Use this when the output color or gray channels are made linear to avoid fairly
 severe accuracy loss.
 
-   if (bit_depth < 16)
-      png_set_expand_16(png_ptr);
+    if (bit_depth < 16)
+       png_set_expand_16(png_ptr);
 
 PNG can have files with 16 bits per channel.  If you only can handle
 8 bits per channel, this will strip the pixels down to 8-bit.
 
     if (bit_depth == 16)
+    {
 #if PNG_LIBPNG_VER >= 10504
        png_set_scale_16(png_ptr);
 #else
        png_set_strip_16(png_ptr);
 #endif
+    }
 
 (The more accurate "png_set_scale_16()" API became available in libpng version
 1.5.4).
@@ -1901,7 +1900,7 @@ Note that png_set_filler() does not change the color type.  If you want
 to do that, you can add a true alpha channel with
 
     if (color_type == PNG_COLOR_TYPE_RGB ||
-       color_type == PNG_COLOR_TYPE_GRAY)
+        color_type == PNG_COLOR_TYPE_GRAY)
        png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
 
 where "filler" contains the alpha value to assign to each pixel.
@@ -1926,7 +1925,7 @@ with alpha.
     if (color_type == PNG_COLOR_TYPE_RGB ||
         color_type == PNG_COLOR_TYPE_RGB_ALPHA)
        png_set_rgb_to_gray(png_ptr, error_action,
-          double red_weight, double green_weight);
+          (double)red_weight, (double)green_weight);
 
     error_action = 1: silently do the conversion
 
@@ -1949,8 +1948,8 @@ In the corresponding fixed point API the red_weight and green_weight values are
 simply scaled by 100,000:
 
     png_set_rgb_to_gray(png_ptr, error_action,
-       png_fixed_point red_weight,
-       png_fixed_point green_weight);
+       (png_fixed_point)red_weight,
+       (png_fixed_point)green_weight);
 
 If you have set error_action = 1 or 2, you can
 later check whether the image really was gray, after processing
@@ -2186,9 +2185,8 @@ do your own check for number_of_rows*width*pixel_size if you are using
 a multiple-row buffer:
 
    /* Guard against integer overflow */
-   if (number_of_rows > PNG_SIZE_MAX/(width*pixel_size)) {
-        png_error(png_ptr,"image_data buffer would be too large");
-   }
+   if (number_of_rows > PNG_SIZE_MAX/(width*pixel_size))
+      png_error(png_ptr, "image_data buffer would be too large");
 
 Remember: Before you call png_read_update_info(), the png_get_*()
 functions return the values corresponding to the original PNG image.
@@ -2408,12 +2406,11 @@ separate.
 
     if (!end_info)
     {
-       png_destroy_read_struct(&png_ptr, &info_ptr,
-           (png_infopp)NULL);
+       png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
        return ERROR;
     }
 
-   png_read_end(png_ptr, end_info);
+    png_read_end(png_ptr, end_info);
 
 If you are not interested, you should still call png_read_end()
 but you can pass NULL, avoiding the need to create an end_info structure.
@@ -2421,7 +2418,7 @@ If you do this, libpng will not process any chunks after IDAT other than
 skipping over them and perhaps (depending on whether you have called
 png_set_crc_action) checking their CRCs while looking for the IEND chunk.
 
-   png_read_end(png_ptr, (png_infop)NULL);
+   png_read_end(png_ptr, NULL);
 
 If you don't call png_read_end(), then your file pointer will be
 left pointing to the first chunk after the last IDAT, which is probably
@@ -2430,13 +2427,11 @@ the PNG datastream.
 
 When you are done, you can free all memory allocated by libpng like this:
 
-   png_destroy_read_struct(&png_ptr, &info_ptr,
-       &end_info);
+   png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
 
 or, if you didn't create an end_info structure,
 
-   png_destroy_read_struct(&png_ptr, &info_ptr,
-       (png_infopp)NULL);
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
 
 It is also possible to individually free the info_ptr members that
 point to libpng-allocated storage with the following function:
@@ -2556,15 +2551,13 @@ png_infop info_ptr;
 
     if (!info_ptr)
     {
-       png_destroy_read_struct(&png_ptr,
-          (png_infopp)NULL, (png_infopp)NULL);
+       png_destroy_read_struct(&png_ptr, NULL, NULL);
        return ERROR;
     }
 
     if (setjmp(png_jmpbuf(png_ptr)))
     {
-       png_destroy_read_struct(&png_ptr, &info_ptr,
-          (png_infopp)NULL);
+       png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
        return ERROR;
     }
 
@@ -2597,8 +2590,7 @@ png_infop info_ptr;
  {
     if (setjmp(png_jmpbuf(png_ptr)))
     {
-       png_destroy_read_struct(&png_ptr, &info_ptr,
-           (png_infopp)NULL);
+       png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
        return ERROR;
     }
 
@@ -2763,8 +2755,7 @@ both "png_ptr"; you can call them anything you like, such as
     png_infop info_ptr = png_create_info_struct(png_ptr);
     if (!info_ptr)
     {
-       png_destroy_write_struct(&png_ptr,
-           (png_infopp)NULL);
+       png_destroy_write_struct(&png_ptr, NULL);
        return ERROR;
     }
 
@@ -2790,7 +2781,7 @@ section below for more information on the libpng error handling.
 
     if (setjmp(png_jmpbuf(png_ptr)))
     {
-    png_destroy_write_struct(&png_ptr, &info_ptr);
+       png_destroy_write_struct(&png_ptr, &info_ptr);
        fclose(fp);
        return ERROR;
     }
@@ -2844,9 +2835,9 @@ a progress meter or the like.  It's demonstrated in pngtest.c.
 You must supply a function
 
     void write_row_callback(png_structp png_ptr, png_uint_32 row,
-       int pass);
+       int pass)
     {
-      /* put your code here */
+       /* put your code here */
     }
 
 (You can give it another name that you like instead of "write_row_callback")
@@ -3116,8 +3107,8 @@ width, height, bit_depth, and color_type must be the same in each call.
 
     png_set_eXIf_1(png_ptr, info_ptr, num_exif, exif);
 
-    exif           - Exif profile (array of
-                     png_byte) (PNG_INFO_eXIf)
+    exif           - Exif profile (array of png_byte)
+                     (PNG_INFO_eXIf)
 
     png_set_hIST(png_ptr, info_ptr, hist);
 
@@ -3127,12 +3118,12 @@ width, height, bit_depth, and color_type must be the same in each call.
     png_set_tIME(png_ptr, info_ptr, mod_time);
 
     mod_time       - time image was last modified
-                     (PNG_VALID_tIME)
+                     (PNG_INFO_tIME)
 
     png_set_bKGD(png_ptr, info_ptr, background);
 
     background     - background color (of type
-                     png_color_16p) (PNG_VALID_bKGD)
+                     png_color_16p) (PNG_INFO_bKGD)
 
     png_set_text(png_ptr, info_ptr, text_ptr, num_text);
 
@@ -4218,7 +4209,7 @@ png_create_read_struct_2() or png_create_write_struct_2() to register your
 own functions as described above.  These functions also provide a void
 pointer that can be retrieved via
 
-    mem_ptr=png_get_mem_ptr(png_ptr);
+    mem_ptr = png_get_mem_ptr(png_ptr);
 
 Your replacement memory functions must have prototypes as follows:
 
@@ -4515,7 +4506,7 @@ When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
 can still use PNG_DEBUG to control your own debugging:
 
    #ifdef PNG_DEBUG
-       fprintf(stderr, ...
+       fprintf(stderr, ...);
    #endif
 
 When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
@@ -4692,7 +4683,7 @@ deprecated since libpng-1.0.16 and libpng-1.2.6.
 The function
     png_check_sig(sig, num)
 was replaced with
-    !png_sig_cmp(sig, 0, num)
+    png_sig_cmp(sig, 0, num) == 0
 It has been deprecated since libpng-0.90.
 
 The function
@@ -4756,8 +4747,8 @@ png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
 png_set_asm_flags(), and png_mmx_supported()
 
 We removed the obsolete png_check_sig(), png_memcpy_check(), and
-png_memset_check() functions.  Instead use !png_sig_cmp(), memcpy(),
-and memset(), respectively.
+png_memset_check() functions.  Instead use png_sig_cmp() == 0,
+memcpy(), and memset(), respectively.
 
 The function png_set_gray_1_2_4_to_8() was removed. It has been
 deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
@@ -5239,7 +5230,7 @@ changed, and is unaffected by conditional compilation macros.  It is the
 best choice for use in configure scripts for detecting the presence of any
 libpng version since 0.88.  In an autoconf "configure.in" you could use
 
-    AC_CHECK_LIB(png, png_get_io_ptr, ...
+    AC_CHECK_LIB(png, png_get_io_ptr, ...)
 
 XV. Source code repository
 
@@ -5248,12 +5239,12 @@ control.  The git repository was built from old libpng-x.y.z.tar.gz files
 going back to version 0.70.  You can access the git repository (read only)
 at
 
-    https://github.com/glennrp/libpng or
+    https://github.com/pnggroup/libpng or
     https://git.code.sf.net/p/libpng/code.git
 
 or you can browse it with a web browser at
 
-    https://github.com/glennrp/libpng or
+    https://github.com/pnggroup/libpng or
     https://sourceforge.net/p/libpng/code/ci/libpng16/tree/
 
 Patches can be sent to png-mng-implement at lists.sourceforge.net or
@@ -5263,7 +5254,7 @@ uploaded to the libpng bug tracker at
 
 or as a "pull request" to
 
-    https://github.com/glennrp/libpng/pulls
+    https://github.com/pnggroup/libpng/pulls
 
 We also accept patches built from the tar or zip distributions, and
 simple verbal descriptions of bug fixes, reported either to the
diff --git a/src/3rdparty/libpng/png.c b/src/3rdparty/libpng/png.c
index e411381f8f..cf9f361070 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_41 Your_png_h_is_not_version_1_6_41;
+typedef png_libpng_version_1_6_42 Your_png_h_is_not_version_1_6_42;
 
 /* 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 1.6.41" PNG_STRING_NEWLINE \
+      "libpng version 1.6.42" 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 \
diff --git a/src/3rdparty/libpng/png.h b/src/3rdparty/libpng/png.h
index d78c779934..f537c5bb08 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 1.6.41
+ * libpng version 1.6.42
  *
  * 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 1.6.41, January 2024:
+ *   libpng versions 1.6.36, December 2018, through 1.6.42, January 2024:
  *     Cosmin Truta
  *   See also "Contributing Authors", below.
  */
@@ -239,7 +239,7 @@
  *    ...
  *    1.5.30                  15    10530  15.so.15.30[.0]
  *    ...
- *    1.6.41                  16    10641  16.so.16.41[.0]
+ *    1.6.42                  16    10641  16.so.16.41[.0]
  *
  *    Henceforth the source version will match the shared-library major and
  *    minor numbers; the shared-library major version number will be used for
@@ -278,7 +278,7 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.41"
+#define PNG_LIBPNG_VER_STRING "1.6.42"
 #define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
@@ -318,7 +318,7 @@
  * From version 1.0.1 it is:
  * XXYYZZ, where XX=major, YY=minor, ZZ=release
  */
-#define PNG_LIBPNG_VER 10641 /* 1.6.41 */
+#define PNG_LIBPNG_VER 10641 /* 1.6.42 */
 
 /* 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_41;
+typedef char* png_libpng_version_1_6_42;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -914,9 +914,9 @@ PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
     size_t num_to_check));
 
 /* Simple signature checking function.  This is the same as calling
- * png_check_sig(sig, n) := (png_sig_cmp(sig, 0, n) != 0).
+ * png_check_sig(sig, n) := (png_sig_cmp(sig, 0, n) == 0).
  */
-#define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) != 0)
+#define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) == 0) /* DEPRECATED */
 
 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
 PNG_EXPORTA(4, png_structp, png_create_read_struct,
diff --git a/src/3rdparty/libpng/pngconf.h b/src/3rdparty/libpng/pngconf.h
index 30c1aad52d..99851f4f9c 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 1.6.41
+ * libpng version 1.6.42
  *
  * 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 d768a8ef08..330453c139 100644
--- a/src/3rdparty/libpng/pnglibconf.h
+++ b/src/3rdparty/libpng/pnglibconf.h
@@ -1,6 +1,6 @@
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.6.41 */
+/* libpng version 1.6.42 */
 
 /* Copyright (c) 2018-2024 Cosmin Truta */
 /* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson */
diff --git a/src/3rdparty/libpng/pngpriv.h b/src/3rdparty/libpng/pngpriv.h
index 3a3e9d3564..9bfdb71342 100644
--- a/src/3rdparty/libpng/pngpriv.h
+++ b/src/3rdparty/libpng/pngpriv.h
@@ -36,7 +36,7 @@
  * still required (as of 2011-05-02.)
  */
 #ifndef _POSIX_SOURCE
-# define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+#  define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
 #endif
 
 #ifndef PNG_VERSION_INFO_ONLY
@@ -190,7 +190,8 @@
 #endif /* PNG_ARM_NEON_OPT > 0 */
 
 #ifndef PNG_MIPS_MSA_OPT
-#  if defined(__mips_msa) && (__mips_isa_rev >= 5) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+#  if defined(__mips_msa) && (__mips_isa_rev >= 5) && \
+   defined(PNG_ALIGNED_MEMORY_SUPPORTED)
 #     define PNG_MIPS_MSA_OPT 2
 #  else
 #     define PNG_MIPS_MSA_OPT 0
@@ -199,7 +200,8 @@
 
 #ifndef PNG_MIPS_MMI_OPT
 #  ifdef PNG_MIPS_MMI
-#    if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+#    if defined(__mips_loongson_mmi) && (_MIPS_SIM == _ABI64) && \
+     defined(PNG_ALIGNED_MEMORY_SUPPORTED)
 #       define PNG_MIPS_MMI_OPT 1
 #    else
 #       define PNG_MIPS_MMI_OPT 0
@@ -231,7 +233,7 @@
        * enable SSE optimizations.  This means that these optimizations will
        * be off by default.  See contrib/intel for more details.
        */
-#     if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
+#      if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
        defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
        (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
 #         define PNG_INTEL_SSE_OPT 1
diff --git a/src/3rdparty/libpng/qt_attribution.json b/src/3rdparty/libpng/qt_attribution.json
index 90aae019a4..3268d74d6e 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": "1.6.41",
-    "DownloadLocation": "https://download.sourceforge.net/libpng/libpng-1.6.41.tar.xz",
+    "Version": "1.6.42",
+    "DownloadLocation": "https://download.sourceforge.net/libpng/libpng-1.6.42.tar.xz",
 
     "License": "libpng License and PNG Reference Library version 2",
     "LicenseId": "Libpng AND libpng-2.0",