diff options
| -rw-r--r-- | src/common/compat.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/src/common/compat.c b/src/common/compat.c index 49e66c6a6..e256f45a2 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -345,11 +345,15 @@ tor_asprintf(char **strp, const char *fmt, ...) int tor_vasprintf(char **strp, const char *fmt, va_list args) { + /* use a temporary variable in case *strp is in args. */ + char *strp_tmp=NULL; #ifdef HAVE_VASPRINTF /* If the platform gives us one, use it. */ - int r = vasprintf(strp, fmt, args); + int r = vasprintf(&strp_tmp, fmt, args); if (r < 0) *strp = NULL; + else + *strp = strp_tmp; return r; #elif defined(MS_WINDOWS) /* On Windows, _vsnprintf won't tell us the length of the string if it @@ -358,15 +362,17 @@ tor_vasprintf(char **strp, const char *fmt, va_list args) char *res; len = _vcsprintf(fmt, args); if (len < 0) { - strp = NULL; + *strp = NULL; return -1; } - *strp = tor_malloc(len + 1); - r = _vsnprintf(*strp, len+1, fmt, args); + strp_tmp = tor_malloc(len + 1); + r = _vsnprintf(strp_tmp, len+1, fmt, args); if (r != len) { - tor_free(*strp); + tor_free(strp_tmp); + *strp = NULL; return -1; } + *strp = strp_tmp; return len; #else /* Everywhere else, we have a decent vsnprintf that tells us how many @@ -383,12 +389,14 @@ tor_vasprintf(char **strp, const char *fmt, va_list args) *strp = tor_strdup(buf); return len; } - *strp = tor_malloc(len+1); - r = vsnprintf(*strp, len+1, fmt, args); + strp_tmp = tor_malloc(len+1); + r = vsnprintf(strp_tmp, len+1, fmt, args); if (r != len) { - tor_free(*strp); + tor_free(strp_tmp); + *strp = NULL; return -1; } + *strp = strp_tmp; return len; #endif } |