git-p4: Unset P4DIFF environment variable when using 'p4 -du diff'
[gitweb.git] / configure.ac
index 85d7ef570d390d56d3ec3ba8af406eee30d700ea..287149d304b8a631d879bd3be7b059c6f074e5fe 100644 (file)
@@ -326,6 +326,40 @@ else
        NO_C99_FORMAT=
 fi
 AC_SUBST(NO_C99_FORMAT)
+#
+# Define SNPRINTF_RETURNS_BOGUS if your are on a system which snprintf()
+# or vsnprintf() return -1 instead of number of characters which would
+# have been written to the final string if enough space had been available.
+AC_CACHE_CHECK([whether snprintf() and/or vsnprintf() return bogus value],
+ [ac_cv_snprintf_returns_bogus],
+[
+AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
+               #include "stdarg.h"
+
+               int test_vsnprintf(char *str, size_t maxsize, const char *format, ...)
+               {
+                 int ret;
+                 va_list ap;
+                 va_start(ap, format);
+                 ret = vsnprintf(str, maxsize, format, ap);
+                 va_end(ap);
+                 return ret;
+               }],
+               [[char buf[6];
+                 if (test_vsnprintf(buf, 3, "%s", "12345") != 5
+                     || strcmp(buf, "12")) return 1;
+                 if (snprintf(buf, 3, "%s", "12345") != 5
+                     || strcmp(buf, "12")) return 1]])],
+       [ac_cv_snprintf_returns_bogus=no],
+       [ac_cv_snprintf_returns_bogus=yes])
+])
+if test $ac_cv_snprintf_returns_bogus = yes; then
+       SNPRINTF_RETURNS_BOGUS=UnfortunatelyYes
+else
+       SNPRINTF_RETURNS_BOGUS=
+fi
+AC_SUBST(SNPRINTF_RETURNS_BOGUS)
 
 
 ## Checks for library functions.