From 021ba32a7bca954235e31338c4f27b221a1807de Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Fri, 10 Apr 2020 15:43:41 -0400
Subject: [PATCH] remote: drop auto-strlen behavior of make_branch() and
 make_rewrite()

The make_branch() and make_rewrite() functions can take a NUL-terminated
string or a ptr/len pair. They use a sentinel value of "0" for the len
to tell the difference between the two. However, when parsing config
like:

  [branch ""]
  merge = whatever

whose key flattens to:

  branch..merge

we might actually have a zero-length branch name. This is obviously
nonsense, but the current code would consider it as a NUL-terminated
string and use the branch name ".merge".

We could use a better sentinel value here (like "-1"), but that gets in
the way of moving to size_t, which is a more appropriate type for a
ptr/len combo.

Let's instead just drop this feature and have the callers (of which
there are only two total) use strlen() themselves. This simplifies the
code, and lets us move to using size_t.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 remote.c | 35 ++++++++++++-----------------------
 1 file changed, 12 insertions(+), 23 deletions(-)

diff --git a/remote.c b/remote.c
index c43196ec06..35bc3f9f2d 100644
--- a/remote.c
+++ b/remote.c
@@ -174,54 +174,43 @@ static void add_merge(struct branch *branch, const char *name)
 	branch->merge_name[branch->merge_nr++] = name;
 }
 
-static struct branch *make_branch(const char *name, int len)
+static struct branch *make_branch(const char *name, size_t len)
 {
 	struct branch *ret;
 	int i;
 
 	for (i = 0; i < branches_nr; i++) {
-		if (len ? (!strncmp(name, branches[i]->name, len) &&
-			   !branches[i]->name[len]) :
-		    !strcmp(name, branches[i]->name))
+		if (!strncmp(name, branches[i]->name, len) &&
+		    !branches[i]->name[len])
 			return branches[i];
 	}
 
 	ALLOC_GROW(branches, branches_nr + 1, branches_alloc);
 	ret = xcalloc(1, sizeof(struct branch));
 	branches[branches_nr++] = ret;
-	if (len)
-		ret->name = xstrndup(name, len);
-	else
-		ret->name = xstrdup(name);
+	ret->name = xstrndup(name, len);
 	ret->refname = xstrfmt("refs/heads/%s", ret->name);
 
 	return ret;
 }
 
-static struct rewrite *make_rewrite(struct rewrites *r, const char *base, int len)
+static struct rewrite *make_rewrite(struct rewrites *r,
+				    const char *base, size_t len)
 {
 	struct rewrite *ret;
 	int i;
 
 	for (i = 0; i < r->rewrite_nr; i++) {
-		if (len
-		    ? (len == r->rewrite[i]->baselen &&
-		       !strncmp(base, r->rewrite[i]->base, len))
-		    : !strcmp(base, r->rewrite[i]->base))
+		if (len == r->rewrite[i]->baselen &&
+		    !strncmp(base, r->rewrite[i]->base, len))
 			return r->rewrite[i];
 	}
 
 	ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
 	ret = xcalloc(1, sizeof(struct rewrite));
 	r->rewrite[r->rewrite_nr++] = ret;
-	if (len) {
-		ret->base = xstrndup(base, len);
-		ret->baselen = len;
-	}
-	else {
-		ret->base = xstrdup(base);
-		ret->baselen = strlen(base);
-	}
+	ret->base = xstrndup(base, len);
+	ret->baselen = len;
 	return ret;
 }
 
@@ -470,7 +459,7 @@ static void read_config(void)
 		const char *head_ref = resolve_ref_unsafe("HEAD", 0, NULL, &flag);
 		if (head_ref && (flag & REF_ISSYMREF) &&
 		    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
-			current_branch = make_branch(head_ref, 0);
+			current_branch = make_branch(head_ref, strlen(head_ref));
 		}
 	}
 	git_config(handle_config, NULL);
@@ -1584,7 +1573,7 @@ struct branch *branch_get(const char *name)
 	if (!name || !*name || !strcmp(name, "HEAD"))
 		ret = current_branch;
 	else
-		ret = make_branch(name, 0);
+		ret = make_branch(name, strlen(name));
 	set_merge(ret);
 	return ret;
 }
-- 
2.11.4.GIT