added define flag SNPRINTF_RETURN_ZERO to indicate that snprintf returns zero if buffer too small

    use flag SNPRINTF_RETURN_ZERO
    emulate snprintf behavior by writing to _big_ buffer if set
    use my_vsnprintf if HAVE_SNPRINTF is not set and set SNPRINTF_RETURN_ZERO in that case


configure.in:
  added define flag to indicate that snprintf returns zero if buffer too small
ndb/src/common/util/basestring_vsnprintf.c:
  use flag SNPRINTF_RETURN_ZERO
  emulate snprintf behavior by writing to _big_ buffer if set
  use my_vsnprintf if HAVE_SNPRINTF is not set and set SNPRINTF_RETURN_ZERO in that case

1 files changed, 21 insertions, 1 deletions

diff --git a/ndb/src/common/util/basestring_vsnprintf.c b/ndb/src/common/util/basestring_vsnprintf.c
index 10932226d18..87ffb8ad146 100644
--- a/ndb/src/common/util/basestring_vsnprintf.c
+++ b/ndb/src/common/util/basestring_vsnprintf.c
@@ -18,6 +18,7 @@
 #define _XOPEN_SOURCE 500
 #include <stdio.h>
 #include <basestring_vsnprintf.h>
+#include <my_config.h>
 
 int
 basestring_snprintf(char *str, size_t size, const char *format, ...)
@@ -30,8 +31,27 @@ basestring_snprintf(char *str, size_t size, const char *format, ...)
   return(ret);
 }
 
+#ifdef HAVE_SNPRINTF
+  #define BASESTRING_VSNPRINTF_FUNC(a,b,c,d) vsnprintf(a,b,c,d)
+#else
+  #define SNPRINTF_RETURN_ZERO
+  #define BASESTRING_VSNPRINTF_FUNC(a,b,c,d) my_vsnprintf(a,b,c,d)
+  extern int my_vsnprintf(char *str, size_t size, const char *format, va_list ap);
+#endif
+
+#ifdef SNPRINTF_RETURN_ZERO
+static char basestring_vsnprintf_buf[16*1024];
+#endif
 int
 basestring_vsnprintf(char *str, size_t size, const char *format, va_list ap)
 {
-  return(vsnprintf(str, size, format, ap));
+  int ret= BASESTRING_VSNPRINTF_FUNC(str, size, format, ap);
+#ifdef SNPRINTF_RETURN_ZERO
+  if (ret == 0 && format != 0 && format[0] != '\0') {
+    ret= BASESTRING_VSNPRINTF_FUNC(basestring_vsnprintf_buf,
+				   sizeof(basestring_vsnprintf_buf),
+				   format, ap);
+  }
+#endif
+  return ret;
 }