From 48e1c3f2a59544cc07554f5a06fb4bc6f8769b7e Mon Sep 17 00:00:00 2001 From: bernie Date: Tue, 16 Nov 2004 21:15:19 +0000 Subject: [PATCH] Fix off-by-one bug in [v]snprintf(). git-svn-id: https://src.develer.com/svnoss/bertos/trunk@275 38d2e660-2303-0410-9eaa-f027e97ec537 --- mware/sprintf.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/mware/sprintf.c b/mware/sprintf.c index ddecf8de..dacb06c6 100755 --- 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; } -- 2.25.1