Remove HAVE_LIMITS_H

The `<limits.h>` header file is part of the standard C89 headers [1] and
on current systems there is no need to manually check if header is
present anymore.

Since the libgd requires at least C89 or greater, the `HAVE_LIMITS_H`
symbol defined by Autoconf in configure.ac [2], and Cmake build system
files can be removed and simplifed.

Refs:
[1] https://port70.net/~nsz/c/c89/c89-draft.html#4.1.2
[2] https://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/headers.m4

VMS/CONFIGURE.COM

@@ -889,12 +889,6 @@ $COPY SYS$INPUT [.SRC]CONFIG.H
 /* Define to 1 if you have the <libpng/png.h> header file. */
 /* #undef HAVE_LIBPNG_PNG_H */
 
-
-
-/* Define to 1 if you have the <limits.h> header file. */
-//#define HAVE_LIMITS_H 1
-
-
 /* Define to 1 if you have the <memory.h> header file. */
 #define HAVE_MEMORY_H 1
 

cmake/modules/AC_HEADER_STDC.cmake

@@ -2,7 +2,6 @@
 
 check_include_files(dirent.h HAVE_DIRENT_H)
 check_include_files(inttypes.h HAVE_INTTYPES_H)
-check_include_files(limits.h HAVE_LIMITS_H)
 check_include_files(stddef.h HAVE_STDDEF_H)
 check_include_files(stdint.h HAVE_STDINT_H)
 check_include_files(stdlib.h HAVE_STDLIB_H)

configure.ac

@@ -61,7 +61,6 @@ AC_HEADER_STDC
 AC_CHECK_HEADERS_ONCE(m4_flatten([
 	dirent.h
 	inttypes.h
-	limits.h
 	stddef.h
 	stdint.h
 	stdlib.h

src/config.h.cmake

@@ -60,9 +60,6 @@
 /* Define if you have zlib */
 #cmakedefine HAVE_LIBZ
 
-/* Define to 1 if you have the <limits.h> header file. */
-#cmakedefine HAVE_LIMITS_H
-
 /* Define to 1 if you have the <memory.h> header file. */
 #cmakedefine HAVE_MEMORY_H
 

src/gd_intern.h

@@ -1,10 +1,7 @@
 #ifndef GD_INTERN_H
 #define GD_INTERN_H
 
-#ifdef HAVE_LIMITS_H
 #include <limits.h>
-#endif
-
 
 #ifndef MAXPATHLEN
 # ifdef PATH_MAX

windows/msys/Makefile

@@ -8,7 +8,7 @@ LIBVER=3.0.1
 
 # Misc. config flags.
 CDEFS=-DHAVE_ICONV -DHAVE_ICONV_H		\
--DHAVE_ICONV_T_DEF -DHAVE_INTTYPES_H -DHAVE_LIMITS_H -DHAVE_STDDEF_H	\
+-DHAVE_ICONV_T_DEF -DHAVE_INTTYPES_H -DHAVE_STDDEF_H	\
 -DHAVE_STDINT_H -DHAVE_STDLIB_H -DHAVE_VISIBILITY -DICONV_CONST
 
 # GnuWin32 libs should all be installed in one place.