Forward port libpng16 fixes

Batched fixes from libpng16: PNG_IMAGE_PNG_SIZE_MAX macro fix, contrib/libtests
exit(77) change to just do that for configure and changes to pngstest to
(by default) make random backgrounds on a per-file, not per-session, basis.

Signed-off-by: John Bowler <jbowler@acm.org>

contrib/libtests/pngimage.c

@@ -36,6 +36,15 @@
 #  include <setjmp.h> /* because png.h did *not* include this */
 #endif
 
+/* 1.6.1 added support for the configure test harness, which uses 77 to indicate
+ * a skipped test, in earlier versions we need to succeed on a skipped test, so:
+ */
+#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
+#  define SKIP 77
+#else
+#  define SKIP 0
+#endif
+
 #if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED)\
     && (defined(PNG_READ_PNG_SUPPORTED) || PNG_LIBPNG_VER < 10700)
 /* If a transform is valid on both read and write this implies that if the
@@ -1682,6 +1691,6 @@ int
 main(void)
 {
    fprintf(stderr, "pngimage: no support for png_read/write_image\n");
-   return 77;
+   return SKIP;
 }
 #endif

contrib/libtests/pngstest.c

@@ -26,6 +26,15 @@
 #  include <config.h>
 #endif
 
+/* 1.6.1 added support for the configure test harness, which uses 77 to indicate
+ * a skipped test, in earlier versions we need to succeed on a skipped test, so:
+ */
+#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
+#  define SKIP 77
+#else
+#  define SKIP 0
+#endif
+
 /* Define the following to use this test against your installed libpng, rather
  * than the one being built here:
  */
@@ -99,10 +108,18 @@ make_random_bytes(png_uint_32* seed, void* pv, size_t size)
    seed[1] = u1;
 }
 
+static png_uint_32 color_seed[2];
+
+static void
+reseed(void)
+{
+   color_seed[0] = 0x12345678U;
+   color_seed[1] = 0x9abcdefU;
+}
+
 static void
 random_color(png_colorp color)
 {
-   static png_uint_32 color_seed[2] = { 0x12345678, 0x9abcdef };
    make_random_bytes(color_seed, color, sizeof *color);
 }
 
@@ -316,6 +333,9 @@ compare_16bit(int v1, int v2, int error_limit, int multiple_algorithms)
 #define ACCUMULATE 64
 #define FAST_WRITE 128
 #define sRGB_16BIT 256
+#define NO_RESEED  512   /* do not reseed on each new file */
+#define GBG_ERROR 1024   /* do not ignore the gamma+background_rgb_to_gray
+                          * libpng warning. */
 
 static void
 print_opts(png_uint_32 opts)
@@ -324,8 +344,8 @@ print_opts(png_uint_32 opts)
       printf(" --file");
    if (opts & USE_STDIO)
       printf(" --stdio");
-   if (opts & STRICT)
-      printf(" --strict");
+   if (!(opts & STRICT))
+      printf(" --nostrict");
    if (opts & VERBOSE)
       printf(" --verbose");
    if (opts & KEEP_TMPFILES)
@@ -338,6 +358,12 @@ print_opts(png_uint_32 opts)
       printf(" --slow");
    if (opts & sRGB_16BIT)
       printf(" --sRGB-16bit");
+   if (opts & NO_RESEED)
+      printf(" --noreseed");
+#if PNG_LIBPNG_VER < 10700 /* else on by default */
+   if (opts & GBG_ERROR)
+      printf(" --fault-gbg-warning");
+#endif
 }
 
 #define FORMAT_NO_CHANGE 0x80000000 /* additional flag */
@@ -741,8 +767,15 @@ checkopaque(Image *image)
       return logerror(image, image->file_name, ": opaque not NULL", "");
    }
 
-   else if (image->image.warning_or_error != 0 && (image->opts & STRICT) != 0)
-      return logerror(image, image->file_name, " --strict", "");
+   /* Separate out the gamma+background_rgb_to_gray warning because it may
+    * produce opaque component errors:
+    */
+   else if (image->image.warning_or_error != 0 &&
+            (strcmp(image->image.message,
+               "libpng does not support gamma+background+rgb_to_gray") == 0 ?
+                  (image->opts & GBG_ERROR) != 0 : (image->opts & STRICT) != 0))
+      return logerror(image, image->file_name, (image->opts & GBG_ERROR) != 0 ?
+                      " --fault-gbg-warning" : " --strict", "");
 
    else
       return 1;
@@ -3198,9 +3231,11 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
       if (png_image_write_get_memory_size(image->image, size, convert_to_8bit,
                image->buffer+16, (png_int_32)image->stride, image->colormap))
       {
-         /* This is non-fatal: */
+         /* This is non-fatal but ignoring it was causing serious problems in
+          * the macro to be ignored:
+          */
          if (size > PNG_IMAGE_PNG_SIZE_MAX(image->image))
-            logerror(image, "memory", ": PNG_IMAGE_SIZE_MAX wrong", "");
+            return logerror(image, "memory", ": PNG_IMAGE_SIZE_MAX wrong", "");
 
          initimage(output, image->opts, "memory", image->stride_extra);
          output->input_memory = malloc(size);
@@ -3213,9 +3248,10 @@ write_one_file(Image *output, Image *image, int convert_to_8bit)
                   &output->input_memory_size, convert_to_8bit, image->buffer+16,
                   (png_int_32)image->stride, image->colormap))
             {
-               /* This is also non-fatal (maybe): */
+               /* This is also non-fatal but it safes safer to error out anyway:
+                */
                if (size != output->input_memory_size)
-                  logerror(image, "memory", ": memory size wrong", "");
+                  return logerror(image, "memory", ": memory size wrong", "");
             }
 
             else
@@ -3403,6 +3439,8 @@ test_one_file(const char *file_name, format_list *formats, png_uint_32 opts,
    int result;
    Image image;
 
+   if (!(opts & NO_RESEED))
+      reseed(); /* ensure that the random numbers don't depend on file order */
    newimage(&image);
    initimage(&image, opts, file_name, stride_extra);
    result = read_one_file(&image);
@@ -3440,7 +3478,7 @@ test_one_file(const char *file_name, format_list *formats, png_uint_32 opts,
 int
 main(int argc, char **argv)
 {
-   png_uint_32 opts = FAST_WRITE;
+   png_uint_32 opts = FAST_WRITE | STRICT;
    format_list formats;
    const char *touch = NULL;
    int log_pass = 0;
@@ -3449,11 +3487,17 @@ main(int argc, char **argv)
    int retval = 0;
    int c;
 
+#if PNG_LIBPNG_VER >= 10700
+      /* This error should not exist in 1.7 or later: */
+      opts |= GBG_ERROR;
+#endif
+
    init_sRGB_to_d();
 #if 0
    init_error_via_linear();
 #endif
    format_init(&formats);
+   reseed(); /* initialize random number seeds */
 
    for (c=1; c<argc; ++c)
    {
@@ -3470,7 +3514,7 @@ main(int argc, char **argv)
 #        ifdef PNG_STDIO_SUPPORTED
             opts |= USE_FILE;
 #        else
-            return 77; /* skipped: no support */
+            return SKIP; /* skipped: no support */
 #        endif
       else if (strcmp(arg, "--memory") == 0)
          opts &= ~USE_FILE;
@@ -3478,7 +3522,7 @@ main(int argc, char **argv)
 #        ifdef PNG_STDIO_SUPPORTED
             opts |= USE_STDIO;
 #        else
-            return 77; /* skipped: no support */
+            return SKIP; /* skipped: no support */
 #        endif
       else if (strcmp(arg, "--name") == 0)
          opts &= ~USE_STDIO;
@@ -3504,10 +3548,16 @@ main(int argc, char **argv)
          opts &= ~KEEP_GOING;
       else if (strcmp(arg, "--strict") == 0)
          opts |= STRICT;
+      else if (strcmp(arg, "--nostrict") == 0)
+         opts &= ~STRICT;
       else if (strcmp(arg, "--sRGB-16bit") == 0)
          opts |= sRGB_16BIT;
       else if (strcmp(arg, "--linear-16bit") == 0)
          opts &= ~sRGB_16BIT;
+      else if (strcmp(arg, "--noreseed") == 0)
+         opts |= NO_RESEED;
+      else if (strcmp(arg, "--fault-gbg-warning") == 0)
+         opts |= GBG_ERROR;
       else if (strcmp(arg, "--tmpfile") == 0)
       {
          if (c+1 < argc)
@@ -3764,6 +3814,6 @@ int main(void)
 {
    fprintf(stderr, "pngstest: no read support in libpng, test skipped\n");
    /* So the test is skipped: */
-   return 77;
+   return SKIP;
 }
 #endif /* PNG_SIMPLIFIED_READ_SUPPORTED */

contrib/libtests/pngunknown.c

@@ -30,6 +30,16 @@
 #  include "../../png.h"
 #endif
 
+/* 1.6.1 added support for the configure test harness, which uses 77 to indicate
+ * a skipped test, in earlier versions we need to succeed on a skipped test, so:
+ */
+#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
+#  define SKIP 77
+#else
+#  define SKIP 0
+#endif
+
+
 /* Since this program tests the ability to change the unknown chunk handling
  * these must be defined:
  */
@@ -1260,7 +1270,7 @@ main(void)
    fprintf(stderr,
       " test ignored: no support to find out about unknown chunks\n");
    /* So the test is skipped: */
-   return 77;
+   return SKIP;
 }
 #endif /* READ_USER_CHUNKS || SAVE_UNKNOWN_CHUNKS */
 
@@ -1271,6 +1281,6 @@ main(void)
    fprintf(stderr,
       " test ignored: no support to modify unknown chunk handling\n");
    /* So the test is skipped: */
-   return 77;
+   return SKIP;
 }
 #endif /* SET_UNKNOWN_CHUNKS && READ*/

contrib/libtests/pngvalid.c

@@ -62,10 +62,10 @@
 /* 1.6.1 added support for the configure test harness, which uses 77 to indicate
  * a skipped test, in earlier versions we need to succeed on a skipped test, so:
  */
-#if PNG_LIBPNG_VER < 10601
-#  define SKIP 0
-#else
+#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
 #  define SKIP 77
+#else
+#  define SKIP 0
 #endif
 
 /* pngvalid requires write support and one of the fixed or floating point APIs.

png.h

@@ -3569,8 +3569,9 @@ PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
    ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
     (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
-     12U+PNG_IMAGE_COLORMAP_SIZE(image)/*PLTE+tRNS data*/+\
-     (((image).format&PNG_FORMAT_FLAG_ALPHA)?12U/*tRNS*/:0U):0U)+\
+     12U+3U*(image).colormap_entries/*PLTE data*/+\
+     (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
+      12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
     12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
    /* A helper for the following macro; if your compiler cannot handle the
     * following macro use this one with the result of