Always check return value of strftime().

strftime() returns 0 and leaves the contents of the output buffer
unspecified if the output buffer is not big enough.  Thus, one should
check strftime()'s return value.  Until now, OVS has had a few invocations
of strftime() that did not check the return value.  This commit fixes
those.  I believe that the buffers were always large enough in each case,
but it's better to be safe.

Reported-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/lib/dynamic-string.h b/lib/dynamic-string.h
index 098caafe7..b988e1f2d 100644
--- a/lib/dynamic-string.h
+++ b/lib/dynamic-string.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,10 +22,9 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <time.h>
 #include "compiler.h"
 
-struct tm;
-
 /* A "dynamic string", that is, a buffer that can be used to construct a
  * string across a series of operations that extend or modify it.
  *
@@ -56,14 +55,17 @@ void ds_put_format(struct ds *, const char *, ...) PRINTF_FORMAT(2, 3);
 void ds_put_format_valist(struct ds *, const char *, va_list)
     PRINTF_FORMAT(2, 0);
 void ds_put_printable(struct ds *, const char *, size_t);
-void ds_put_strftime(struct ds *, const char *, bool utc)
-    STRFTIME_FORMAT(2);
 void ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
                      uintptr_t ofs, bool ascii);
 int ds_get_line(struct ds *, FILE *);
 int ds_get_preprocessed_line(struct ds *, FILE *);
 int ds_get_test_line(struct ds *, FILE *);
 
+void ds_put_strftime(struct ds *, const char *template, time_t when, bool utc)
+    STRFTIME_FORMAT(2);
+char *xastrftime(const char *template, time_t when, bool utc)
+    STRFTIME_FORMAT(1);
+
 char *ds_cstr(struct ds *);
 const char *ds_cstr_ro(const struct ds *);
 char *ds_steal_cstr(struct ds *);