Merge branch 'ph/strbuf'

* ph/strbuf: (44 commits)
  Make read_patch_file work on a strbuf.
  strbuf_read_file enhancement, and use it.
  strbuf change: be sure ->buf is never ever NULL.
  double free in builtin-update-index.c
  Clean up stripspace a bit, use strbuf even more.
  Add strbuf_read_file().
  rerere: Fix use of an empty strbuf.buf
  Small cache_tree_write refactor.
  Make builtin-rerere use of strbuf nicer and more efficient.
  Add strbuf_cmp.
  strbuf_setlen(): do not barf on setting length of an empty buffer to 0
  sq_quote_argv and add_to_string rework with strbuf's.
  Full rework of quote_c_style and write_name_quoted.
  Rework unquote_c_style to work on a strbuf.
  strbuf API additions and enhancements.
  nfv?asprintf are broken without va_copy, workaround them.
  Fix the expansion pattern of the pseudo-static path buffer.
  builtin-for-each-ref.c::copy_name() - do not overstep the buffer.
  builtin-apply.c: fix a tiny leak introduced during xmemdupz() conversion.
  Use xmemdupz() in many places.
  ...

1 files changed, 9 insertions, 11 deletions

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;
 }