[PATCH 1/6] remote: drop auto-strlen behavior of make_branch() and make_rewrite()

From: Jeff King <peff@peff.net>
Date: Apr 10, 2020, 19:43 UTC
Message-ID: <20200410194341.GA1363756@coredump.intra.peff.net>
In-Reply-To: <20200410194211.GA1363484@coredump.intra.peff.net>

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>
---
 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;
 }

-- 
2.26.0.414.ge3a6455e3d