[PATCH 2/3] Change semantics of interpolate to work like snprintf.
Also fix many off-by-ones and a useless memset.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
---
commit.c | 9 ++++-----
interpolate.c | 20 ++++++++------------
2 files changed, 12 insertions(+), 17 deletions(-)
diff --git a/commit.c b/commit.c
index dc5a064..30db9f4 100644
--- a/commit.c
+++ b/commit.c
@@ -922,15 +922,14 @@ static long format_commit_message(const struct commit *commit,
do {
char *buf = *buf_p;
- unsigned long space = *space_p;
+ unsigned long len;
- space = interpolate(buf, space, user_format,
+ len = interpolate(buf, *space_p, user_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 0082677..ff4fb10 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;
@@ -89,14 +86,13 @@ unsigned long interpolate(char *result, unsigned long reslen,
}
}
/* Straight copy one non-interpolation character. */
- if (newlen + 1 < reslen)
+ if (newlen < reslen)
*dest++ = *src;
src++;
newlen++;
}
- if (newlen + 1 < reslen)
- return 0;
- else
- return newlen + 2;
+ if (reslen > 0)
+ *dest = '\0';
+ return newlen;
}
--
1.5.3.1
Pierre Habouzit <madcoder@debian.org>