[libpng17] Document new PNG_ABORT behavior in libpng-1.7.x

ANNOUNCE

@@ -76,6 +76,7 @@ Version 1.7.0alpha03 [December 17, 2012]
     links and tests against zlib with a prefix; tests have been clarified; and
     irrelevant or obsolete things (as defined by the autotools man page) have
     been removed.
+  Documented new PNG_ABORT behavior in the manual and commentary in pngerror.c
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4361,6 +4361,7 @@ Version 1.7.0alpha03 [December 17, 2012]
     links and tests against zlib with a prefix; tests have been clarified; and
     irrelevant or obsolete things (as defined by the autotools man page) have
     been removed.
+  Documented new PNG_ABORT behavior in the manual and commentary in pngerror.c
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

libpng-manual.txt

@@ -432,7 +432,7 @@ If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
 errors will result in a call to PNG_ABORT() which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
@@ -2562,9 +2562,9 @@ section below for more information on the libpng error handling.
 
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
-errors will result in a call to PNG_ABORT() which defaults to abort().
+errors will result in a call to PNG_ABORT which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
@@ -3943,7 +3943,7 @@ Error handling in libpng is done through png_error() and png_warning().
 Errors handled through png_error() are fatal, meaning that png_error()
 should never return to its caller.  Currently, this is handled via
 setjmp() and longjmp() (unless you have compiled libpng with
-PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT),
 but you could change this to do things like exit() if you should wish,
 as long as your function does not return.
 
@@ -4977,6 +4977,25 @@ Some functions that were deprecated in libpng-1.6.0 were removed:
     png_malloc_default(),
     and png_free_default().
 
+The PNG_ABORT() macro was changed to PNG_ABORT, and the default is now
+"abort()" for all platforms (previously it was "ExitProcess(0)" on
+Windows platforms).  Starting with libpng-1.7.0 you have to define
+PNG_ABORT instead of PNG_ABORT(), e.g.,
+
+    #if PNGCRUSH_LIBPNG_VER >= 10700
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT ExitProcess(0);
+    #  else
+    #    define PNG_ABORT abort();
+    #  endif
+    #else
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT() ExitProcess(0)
+    #  else
+    #    define PNG_ABORT() abort()
+    #  endif
+    #endif
+
 The 8-bit compose and rgb_to_grayscale operations were made more accurate.
 While these did not introduce API incompatibility, there may be differences
 in unit test results.

libpng.3

@@ -1409,7 +1409,7 @@ If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
 errors will result in a call to PNG_ABORT() which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
@@ -3539,9 +3539,9 @@ section below for more information on the libpng error handling.
 
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
-errors will result in a call to PNG_ABORT() which defaults to abort().
+errors will result in a call to PNG_ABORT which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
@@ -4920,7 +4920,7 @@ Error handling in libpng is done through png_error() and png_warning().
 Errors handled through png_error() are fatal, meaning that png_error()
 should never return to its caller.  Currently, this is handled via
 setjmp() and longjmp() (unless you have compiled libpng with
-PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT),
 but you could change this to do things like exit() if you should wish,
 as long as your function does not return.
 
@@ -5955,6 +5955,25 @@ Some functions that were deprecated in libpng-1.6.0 were removed:
     png_malloc_default(),
     and png_free_default().
 
+The PNG_ABORT() macro was changed to PNG_ABORT, and the default is now
+"abort()" for all platforms (previously it was "ExitProcess(0)" on
+Windows platforms).  Starting with libpng-1.7.0 you have to define
+PNG_ABORT instead of PNG_ABORT(), e.g.,
+
+    #if PNGCRUSH_LIBPNG_VER >= 10700
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT ExitProcess(0);
+    #  else
+    #    define PNG_ABORT abort();
+    #  endif
+    #else
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT() ExitProcess(0)
+    #  else
+    #    define PNG_ABORT() abort()
+    #  endif
+    #endif
+
 The 8-bit compose and rgb_to_grayscale operations were made more accurate.
 While these did not introduce API incompatibility, there may be differences
 in unit test results.

pngerror.c

@@ -748,10 +748,10 @@ png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
       png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
 #endif
 
-   /* It is an error if control reaches this point, because png_longjmp must not
+   /* If control reaches this point, png_longjmp() must not return. The only
-    * return the only choice is to terminate the whole process (or maybe
+    * choice is to terminate the whole process (or maybe the thread); to do
-    * thread), to do this the ANSI-C abort() function is used unless a different
+    * this the ANSI-C abort() function is used unless a different method is 
-    * method is implemented by overriding the default configuration setting for
+    * implemented by overriding the default configuration setting for
     * PNG_ABORT (see scripts/pnglibconf.dfa).
     *
     * API change: prior to 1.7.0 PNG_ABORT was invoked as a function type macro