use struct strbuf instead of static buffers

Use "struct strbuf" from Git to remove the limit on file path length.

Notes on scan-tree:
This is slightly involved since I decided to pass the strbuf into
add_repo() and modify if whenever a new file name is required, which
should avoid any extra allocations within that function.  The pattern
there is to append the filename, use it and then reset the buffer to its
original length (retaining a trailing '/').

Notes on ui-snapshot:
Since write_archive modifies the argv array passed to it we
copy the argv_array values into a new array of char* and then free the
original argv_array structure and the new array without worrying about
what the values now look like.

Signed-off-by: John Keeping <john@keeping.me.uk>

1 files changed, 22 insertions, 11 deletions

diff --git a/ui-log.c b/ui-log.c
index 8592843..93af0ce 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -243,15 +243,19 @@ static void print_commit(struct commit *commit, struct rev_info *revs)
 	cgit_free_commitinfo(info);
 }
 
-static const char *disambiguate_ref(const char *ref)
+static const char *disambiguate_ref(const char *ref, int *must_free_result)
 {
 	unsigned char sha1[20];
-	const char *longref;
+	struct strbuf longref = STRBUF_INIT;
 
-	longref = fmt("refs/heads/%s", ref);
-	if (get_sha1(longref, sha1) == 0)
-		return longref;
+	strbuf_addf(&longref, "refs/heads/%s", ref);
+	if (get_sha1(longref.buf, sha1) == 0) {
+		*must_free_result = 1;
+		return strbuf_detach(&longref, NULL);
+	}
 
+	*must_free_result = 0;
+	strbuf_release(&longref);
 	return ref;
 }
 
@@ -284,24 +288,26 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
 	struct commit *commit;
 	struct vector vec = VECTOR_INIT(char *);
 	int i, columns = commit_graph ? 4 : 3;
-	char *arg;
+	int must_free_tip = 0;
+	struct strbuf argbuf = STRBUF_INIT;
 
 	/* First argv is NULL */
 	vector_push(&vec, NULL, 0);
 
 	if (!tip)
 		tip = ctx.qry.head;
-	tip = disambiguate_ref(tip);
+	tip = disambiguate_ref(tip, &must_free_tip);
 	vector_push(&vec, &tip, 0);
 
 	if (grep && pattern && *pattern) {
 		pattern = xstrdup(pattern);
 		if (!strcmp(grep, "grep") || !strcmp(grep, "author") ||
 		    !strcmp(grep, "committer")) {
-			arg = fmt("--%s=%s", grep, pattern);
-			vector_push(&vec, &arg, 0);
+			strbuf_addf(&argbuf, "--%s=%s", grep, pattern);
+			vector_push(&vec, &argbuf.buf, 0);
 		}
 		if (!strcmp(grep, "range")) {
+			char *arg;
 			/* Split the pattern at whitespace and add each token
 			 * as a revision expression. Do not accept other
 			 * rev-list options. Also, replace the previously
@@ -336,8 +342,8 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
 	}
 
 	if (path) {
-		arg = "--";
-		vector_push(&vec, &arg, 0);
+		static const char *double_dash_arg = "--";
+		vector_push(&vec, &double_dash_arg, 0);
 		vector_push(&vec, &path, 0);
 	}
 
@@ -430,4 +436,9 @@ void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *pattern
 			      ctx.qry.vpath, 0, NULL, NULL, ctx.qry.showmsg);
 		html("</td></tr>\n");
 	}
+
+	/* If we allocated tip then it is safe to cast away const. */
+	if (must_free_tip)
+		free((char*) tip);
+	strbuf_release(&argbuf);
 }