[libpng16] fix: Update the cICP implementation yet more
For the sake of completeness:
* Add the cICP entry to the list of known chunks to ignore inside
`png_set_keep_unknown_chunks`.
* Handle cICP in `png_read_end`, alongside cHRM, gAMA, iCCP, sRGB.
* In pngtest.c, move the cICP test code near cHRM, gaMA, iCCP, sRGB.
This is a cherry-pick of commit 27c2ac722fd99b8622cead655034208ce96346ac
from branch 'libpng18'.
Reviewed-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
diff --git a/pngread.c b/pngread.c
index 175d601..49e19a4 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1,6 +1,6 @@
/* pngread.c - read a PNG file
*
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 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.
@@ -173,6 +173,7 @@
else if (chunk_name == png_cHRM)
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
+
#ifdef PNG_READ_cICP_SUPPORTED
else if (chunk_name == png_cICP)
png_handle_cICP(png_ptr, info_ptr, length);
@@ -855,6 +856,11 @@
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
+#ifdef PNG_READ_cICP_SUPPORTED
+ else if (chunk_name == png_cICP)
+ png_handle_cICP(png_ptr, info_ptr, length);
+#endif
+
#ifdef PNG_READ_eXIf_SUPPORTED
else if (chunk_name == png_eXIf)
png_handle_eXIf(png_ptr, info_ptr, length);
diff --git a/pngset.c b/pngset.c
index 383a256..462b50c 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,6 +1,6 @@
/* pngset.c - storage of image information into info struct
*
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 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.
@@ -1420,6 +1420,7 @@
static const png_byte chunks_to_ignore[] = {
98, 75, 71, 68, '\0', /* bKGD */
99, 72, 82, 77, '\0', /* cHRM */
+ 99, 73, 67, 80, '\0', /* cICP */
101, 88, 73, 102, '\0', /* eXIf */
103, 65, 77, 65, '\0', /* gAMA */
104, 73, 83, 84, '\0', /* hIST */
diff --git a/pngtest.c b/pngtest.c
index dbbcf1e..c029266 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1,6 +1,6 @@
/* pngtest.c - a test program for libpng
*
- * Copyright (c) 2018-2024 Cosmin Truta
+ * Copyright (c) 2018-2025 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.
@@ -1167,6 +1167,21 @@
#endif
#endif /* Floating point */
#endif /* Fixed point */
+#ifdef PNG_cICP_SUPPORTED
+ {
+ png_byte colour_primaries;
+ png_byte transfer_function;
+ png_byte matrix_coefficients;
+ png_byte video_full_range_flag;
+
+ if (png_get_cICP(read_ptr, read_info_ptr,
+ &colour_primaries, &transfer_function,
+ &matrix_coefficients, &video_full_range_flag) != 0)
+ png_set_cICP(write_ptr, write_info_ptr,
+ colour_primaries, transfer_function,
+ matrix_coefficients, video_full_range_flag);
+ }
+#endif
#ifdef PNG_iCCP_SUPPORTED
{
png_charp name;
@@ -1205,21 +1220,6 @@
png_set_bKGD(write_ptr, write_info_ptr, background);
}
#endif
-#ifdef PNG_cICP_SUPPORTED
- {
- png_byte colour_primaries;
- png_byte transfer_function;
- png_byte matrix_coefficients;
- png_byte video_full_range_flag;
-
- if (png_get_cICP(read_ptr, read_info_ptr,
- &colour_primaries, &transfer_function,
- &matrix_coefficients, &video_full_range_flag) != 0)
- png_set_cICP(write_ptr, write_info_ptr,
- colour_primaries, transfer_function,
- matrix_coefficients, video_full_range_flag);
- }
-#endif
#ifdef PNG_READ_eXIf_SUPPORTED
{
png_bytep exif = NULL;
