Fix off-by-one bug in [v]snprintf().

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@275 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/mware/sprintf.c b/mware/sprintf.c
index ddecf8debd6b1ee20450c745d9f11fe87201ed2f..dacb06c64336bff5510b01a92c83e6b0c0479fc8 100755 (executable)
--- a/mware/sprintf.c
+++ b/mware/sprintf.c
@@ -13,6 +13,9 @@
 
 /*#*
  *#* $Log$
+ *#* Revision 1.6  2004/11/16 21:15:19  bernie
+ *#* Fix off-by-one bug in [v]snprintf().
+ *#*
  *#* Revision 1.5  2004/10/03 18:54:36  bernie
  *#* sprintf(): Fix a serious bug; snprintf(): New function.
  *#*
@@ -111,7 +114,7 @@ static void __sn_put_char(char c, void *ptr)
 {
        struct __sn_state *state = (struct __sn_state *)ptr;
 
-       if (state->len > 0)
+       if (state->len)
        {
                --state->len;
                *state->str++ = c;
@@ -119,16 +122,23 @@ static void __sn_put_char(char c, void *ptr)
 }
 
 
-int PGM_FUNC(vsnprintf)(char * str, size_t size, const char * PGM_ATTR fmt, va_list ap)
+int PGM_FUNC(vsnprintf)(char *str, size_t size, const char * PGM_ATTR fmt, va_list ap)
 {
-       int result;
-       struct __sn_state state = { str, size };
+       int result = 0;
 
-       result = PGM_FUNC(_formatted_write)(
+       /* Make room for traling '\0'. */
+       if (size--)
+       {
+               struct __sn_state state;
+               state.str = str;
+               state.len = size;
+
+               result = PGM_FUNC(_formatted_write)(
                        fmt, (str ? __sn_put_char : __null_put_char), &state, ap);
 
-       /* Terminate string */
-       *state.str = '\0';
+               /* Terminate string. */
+               *state.str = '\0';
+       }
 
        return result;
 }