From 4acfd1b799acf43642a28a22cc794266c25129ef Mon Sep 17 00:00:00 2001 From: Pierre Habouzit Date: Mon, 10 Sep 2007 12:35:05 +0200 Subject: [PATCH] Change semantics of interpolate to work like snprintf. Also fix many off-by-ones and a useless memset. Signed-off-by: Pierre Habouzit Signed-off-by: Junio C Hamano --- commit.c | 9 ++++----- interpolate.c | 20 +++++++++----------- 2 files changed, 13 insertions(+), 16 deletions(-) diff --git a/commit.c b/commit.c index 99f65cee0..25781cc83 100644 --- a/commit.c +++ b/commit.c @@ -923,15 +923,14 @@ long format_commit_message(const struct commit *commit, const void *format, do { char *buf = *buf_p; - unsigned long space = *space_p; + unsigned long len; - space = interpolate(buf, space, format, + len = interpolate(buf, *space_p, format, table, ARRAY_SIZE(table)); - if (!space) + if (len < *space_p) break; - buf = xrealloc(buf, space); + ALLOC_GROW(buf, len + 1, *space_p); *buf_p = buf; - *space_p = space; } while (1); interp_clear_table(table, ARRAY_SIZE(table)); diff --git a/interpolate.c b/interpolate.c index 00826778f..3de583238 100644 --- a/interpolate.c +++ b/interpolate.c @@ -44,9 +44,8 @@ void interp_clear_table(struct interp *table, int ninterps) * { "%%", "%"}, * } * - * Returns 0 on a successful substitution pass that fits in result, - * Returns a number of bytes needed to hold the full substituted - * string otherwise. + * Returns the length of the substituted string (not including the final \0). + * Like with snprintf, if the result is >= reslen, then it overflowed. */ unsigned long interpolate(char *result, unsigned long reslen, @@ -61,8 +60,6 @@ unsigned long interpolate(char *result, unsigned long reslen, int i; char c; - memset(result, 0, reslen); - while ((c = *src)) { if (c == '%') { /* Try to match an interpolation string. */ @@ -78,9 +75,9 @@ unsigned long interpolate(char *result, unsigned long reslen, value = interps[i].value; valuelen = strlen(value); - if (newlen + valuelen + 1 < reslen) { + if (newlen + valuelen < reslen) { /* Substitute. */ - strncpy(dest, value, valuelen); + memcpy(dest, value, valuelen); dest += valuelen; } newlen += valuelen; @@ -95,8 +92,9 @@ unsigned long interpolate(char *result, unsigned long reslen, newlen++; } - if (newlen + 1 < reslen) - return 0; - else - return newlen + 2; + /* XXX: the previous loop always keep room for the ending NUL, + we just need to check if there was room for a NUL in the first place */ + if (reslen > 0) + *dest = '\0'; + return newlen; } -- 2.26.2