[libpng16] PNG_RELEASE_BUILD replaces tests where the code depended on the build base

type and can be defined on the command line, allowing testing in beta builds. Back
ported from libpng17.

ANNOUNCE

@@ -1,4 +1,4 @@
-Libpng 1.6.18beta04 - May 6, 2015
+Libpng 1.6.18beta04 - May 7, 2015
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -46,7 +46,9 @@ Version 1.6.18beta03 [May 6, 2015]
     and an example PNG generation tool, contrib/examples/genpng.c
     (John Bowler).
 
-Version 1.6.18beta04 [May 6, 2015]
+Version 1.6.18beta04 [May 7, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta builds.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -5226,7 +5226,9 @@ Version 1.6.18beta03 [May 6, 2015]
     and an example PNG generation tool, contrib/examples/genpng.c
     (John Bowler).
 
-Version 1.6.18beta04 [May 6, 2015]
+Version 1.6.18beta04 [May 7, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta builds.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngpriv.h

@@ -300,6 +300,22 @@
 #  define PNG_DLL_EXPORT
 #endif
 
+/* This is a global switch to set the compilation for an installed system
+ * (a release build).  It can be set for testing debug builds to ensure that
+ * they will compile when the build type is switched to RC or STABLE, the
+ * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE.  Set this in CPPFLAGS
+ * with either:
+ *
+ *   -DPNG_RELEASE_BUILD Turns on the release compile path
+ *   -DPNG_RELEASE_BUILD=0 Turns it off
+ * or in your pngusr.h with
+ *   #define PNG_RELEASE_BUILD=1 Turns on the release compile path
+ *   #define PNG_RELEASE_BUILD=0 Turns it off
+ */
+#ifndef PNG_RELEASE_BUILD
+#  define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
+#endif
+
 /* SECURITY and SAFETY:
  *
  * libpng is built with support for internal limits on image dimensions and

pngread.c

@@ -63,7 +63,7 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
          /* In stable builds only warn if an application error can be completely
           * handled.
           */
-#        if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+#        if PNG_RELEASE_BUILD
             png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
 #        endif
 #     endif

pngrutil.c

@@ -341,7 +341,7 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
        * are minimal.
        */
       (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
-#if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+#if PNG_RELEASE_BUILD
       png_chunk_warning(png_ptr, msg);
       png_ptr->zowner = 0;
 #else

pngwrite.c

@@ -543,7 +543,7 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
       /* App warnings are warnings in release (or release candidate) builds but
        * are errors during development.
        */
-#if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+#if PNG_RELEASE_BUILD
       png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
 #endif
 

pngwutil.c

@@ -308,7 +308,7 @@ png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
        */
       (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
 #endif
-#if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+#if PNG_RELEASE_BUILD
          png_warning(png_ptr, msg);
 
          /* Attempt sane error recovery */