[devel] Reverted previous change (png_memset loop)

It does not seem to promise any benefit to libpng.

ANNOUNCE

@@ -535,8 +535,6 @@ version 1.4.0beta77 [August 27, 2009]
   Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
 
 version 1.4.0beta78 [August 29, 2009]
-  Added abililty to configure libpng to use a loop instead of memset(),
-    using PNG_USE_MEMSET_LOOP.
 
 version 1.4.0betaN [future]
   Build shared libraries with -lz and sometimes -lm.

CHANGES

@@ -2221,8 +2221,6 @@ version 1.4.0beta77 [August 27, 2009]
   Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
 
 version 1.4.0beta78 [August 29, 2009]
-  Added abililty to configure libpng to use a loop instead of memset(),
-    using PNG_USE_MEMSET_LOOP.
 
 version 1.4.0betaN [future]
   Build shared libraries with -lz and sometimes -lm.

pngconf.h

@@ -698,13 +698,6 @@
 #define PNG_STRING_NEWLINE "\n"
 #endif
 
-/* Added at libpng-1.4.0 */
-#if !defined(PNG_NO_USE_SYSTEM_MEMSET) || defined(PNG_USE_MEMSET_LOOP)
-#  ifndef PNG_USE_SYSTEM_MEMSET
-#    define PNG_USE_SYSTEM_MEMSET
-#  endif
-#endif
-
 /* These are currently experimental features, define them if you want */
 
 /* very little testing */
@@ -1330,16 +1323,6 @@ typedef char            FAR * FAR * FAR * png_charppp;
 #  endif
 #endif
 
-/* Added at libpng-1.4.0 */
-#ifndef PNG_USE_SYSTEM_MEMSET
-# define png_memset(array,value,num) \
-  { \
-  int ipng_memset; \
-  for (ipng_memset=0; ipng_memset<(num); ++ipng_memset) \
-    ((png_bytep)array)[ipng_memset] = (value); \
-  }
-#endif
-
 #if defined(USE_FAR_KEYWORD)
 /* use this to make far-to-near assignments */
 #  define CHECK   1
@@ -1351,9 +1334,7 @@ typedef char            FAR * FAR * FAR * png_charppp;
 #  define png_strlen  _fstrlen
 #  define png_memcmp  _fmemcmp    /* SJT: added */
 #  define png_memcpy  _fmemcpy
-#  ifndef png_memset
 #  define png_memset  _fmemset
-#  endif
 #  define png_sprintf sprintf
 #else
 #  if defined(_WINDOWS_)  /* favor Windows over C runtime fns */
@@ -1364,9 +1345,7 @@ typedef char            FAR * FAR * FAR * png_charppp;
 #    define png_strlen  lstrlenA
 #    define png_memcmp  memcmp
 #    define png_memcpy  CopyMemory
-#  ifndef png_memset
 #    define png_memset  memset
-#  endif
 #    define png_sprintf wsprintfA
 #  else
 #    define CVT_PTR(ptr)         (ptr)
@@ -1376,9 +1355,7 @@ typedef char            FAR * FAR * FAR * png_charppp;
 #    define png_strlen  strlen
 #    define png_memcmp  memcmp      /* SJT: added */
 #    define png_memcpy  memcpy
-#  ifndef png_memset
 #    define png_memset  memset
-#  endif
 #    define png_sprintf sprintf
 #  ifndef PNG_NO_SNPRINTF
 #    ifdef _MSC_VER