Some systems (namely HPUX and Windows) return -1 when maxsize in snprintf()
and in vsnprintf() is reached. So replace snprintf() and vsnprintf()
functions with our own ones that return correct value upon overflow.
Signed-off-by: Michal Rokos <michal.rokos@xxxxxxxxxxx>
diff --git a/Makefile b/Makefile
index ca5aad9..6af7132 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,10 @@ all::
# Define V=1 to have a more verbose compile.
#
+# 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.
+#
# Define FREAD_READS_DIRECTORIES if your are on a system which succeeds
# when attempting to read from an fopen'ed directory.
#
@@ -629,6 +633,10 @@ endif
ifdef NO_C99_FORMAT
BASIC_CFLAGS += -DNO_C99_FORMAT
endif
+ifdef SNPRINTF_RETURNS_BOGUS
+ COMPAT_CFLAGS += -DSNPRINTF_RETURNS_BOGUS
+ COMPAT_OBJS += compat/snprintf.o
+endif
ifdef FREAD_READS_DIRECTORIES
COMPAT_CFLAGS += -DFREAD_READS_DIRECTORIES
COMPAT_OBJS += compat/fopen.o
diff --git a/config.mak.in b/config.mak.in
index ee6c33d..8e1cd5f 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -46,3 +46,4 @@ NO_MKDTEMP=@NO_MKDTEMP@
NO_ICONV=@NO_ICONV@
OLD_ICONV=@OLD_ICONV@
NO_DEFLATE_BOUND=@NO_DEFLATE_BOUND@
+SNPRINTF_RETURNS_BOGUS=@SNPRINTF_RETURNS_BOGUS@
diff --git a/configure.ac b/configure.ac
index 85d7ef5..a3bbfa6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -326,6 +326,38 @@ 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],
+ [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[1];
+ if (test_vsnprintf(buf, 1, "%s", "12345") != 5) return 1;
+ if (snprintf(buf, 1, "%s", "12345") != 5) 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.
diff --git a/git-compat-util.h b/git-compat-util.h
index 2a40703..0aa04eb 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -209,6 +209,15 @@ void *gitmemmem(const void *haystack, size_t haystacklen,
extern FILE *git_fopen(const char*, const char*);
#endif
+#ifdef SNPRINTF_RETURNS_BOGUS
+#define snprintf git_snprintf
+extern int git_snprintf(char *str, size_t maxsize,
+ const char *format, ...);
+#define vsnprintf git_vsnprintf
+extern int git_vsnprintf(char *str, size_t maxsize,
+ const char *format, va_list ap);
+#endif
+
#ifdef __GLIBC_PREREQ
#if __GLIBC_PREREQ(2, 1)
#define HAVE_STRCHRNUL
diff --git a/dev/null b/compat/snprintf.c
new file mode 100644
index 0000000..dbfc2d6
--- /dev/null
+++ b/compat/snprintf.c
@@ -0,0 +1,40 @@
+#include "../git-compat-util.h"
+
+#undef vsnprintf
+int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
+{
+ char *s;
+ int ret;
+
+ ret = vsnprintf(str, maxsize, format, ap);
+ if (ret != -1)
+ return ret;
+
+ s = NULL;
+ if (maxsize < 128)
+ maxsize = 128;
+
+ while (ret == -1) {
+ maxsize *= 4;
+ str = realloc(s, maxsize);
+ if (! str)
+ break;
+ s = str;
+ ret = vsnprintf(str, maxsize, format, ap);
+ }
+ free(s);
+ return ret;
+}
+
+int git_snprintf(char *str, size_t maxsize, const char *format, ...)
+{
+ va_list ap;
+ int ret;
+
+ va_start(ap, format);
+ ret = git_vsnprintf(str, maxsize, format, ap);
+ va_end(ap);
+
+ return ret;
+}
+
--
Michal Rokos
NextSoft s.r.o.
Vyskočilova 1/1410
140 21 Praha 4
phone: +420 267 224 311
fax: +420 267 224 307
mobile: +420 736 646 591
e-mail: michal.rokos@xxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
