Merge branch 'maint-1.7.7' into maint

[git.git] / compat / snprintf.c

diff --git a/compat/snprintf.c b/compat/snprintf.c
index 6c0fb056a571b30627e404d7f164de31ed1a8699..42ea1ac110813bbd16e77cfbc36f16e6a5e9ddb2 100644 (file)
--- a/compat/snprintf.c
+++ b/compat/snprintf.c
@@ -2,11 +2,14 @@
 
 /*
  * The size parameter specifies the available space, i.e. includes
- * the trailing NUL byte; but Windows's vsnprintf expects the
- * number of characters to write without the trailing NUL.
+ * the trailing NUL byte; but Windows's vsnprintf uses the entire
+ * buffer and avoids the trailing NUL, should the buffer be exactly
+ * big enough for the result. Defining SNPRINTF_SIZE_CORR to 1 will
+ * therefore remove 1 byte from the reported buffer size, so we
+ * always have room for a trailing NUL byte.
  */
 #ifndef SNPRINTF_SIZE_CORR
-#if defined(__MINGW32__) && defined(__GNUC__) && __GNUC__ < 4
+#if defined(WIN32) && (!defined(__GNUC__) || __GNUC__ < 4)
 #define SNPRINTF_SIZE_CORR 1
 #else
 #define SNPRINTF_SIZE_CORR 0
@@ -16,11 +19,14 @@
 #undef vsnprintf
 int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
 {
+       va_list cp;
        char *s;
        int ret = -1;
 
        if (maxsize > 0) {
-               ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
+               va_copy(cp, ap);
+               ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, cp);
+               va_end(cp);
                if (ret == maxsize-1)
                        ret = -1;
                /* Windows does not NUL-terminate if result fills buffer */
@@ -39,7 +45,9 @@ int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
                if (! str)
                        break;
                s = str;
-               ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
+               va_copy(cp, ap);
+               ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, cp);
+               va_end(cp);
                if (ret == maxsize-1)
                        ret = -1;
        }