[PATCH 2/6] strbuf_attach: correctly pass in `strlen() + 1` for `alloc`

["Martin Ågren" <martin.agren@gmail.com>]

This is similar to the previous commit where we corrected a use of
`strbuf_attach()` to not pass in the same value for `len` and `alloc`.
The sites addressed in this commit all use `strlen()`, which makes it
obvious that we're working with NUL-terminated strings and that we can
safely switch to providing `len + 1` for `alloc`.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
---
 mailinfo.c           | 2 +-
 path.c               | 2 +-
 refs/files-backend.c | 2 +-
 trailer.c            | 3 ++-
 4 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/mailinfo.c b/mailinfo.c
index 742fa376ab..af5d2cad31 100644
--- a/mailinfo.c
+++ b/mailinfo.c
@@ -459,7 +459,7 @@ static int convert_to_utf8(struct mailinfo *mi,
 		return error("cannot convert from %s to %s",
 			     charset, mi->metainfo_charset);
 	}
-	strbuf_attach(line, out, strlen(out), strlen(out));
+	strbuf_attach(line, out, strlen(out), strlen(out) + 1);
 	return 0;
 }
 
diff --git a/path.c b/path.c
index 9bd717c307..5745a71d36 100644
--- a/path.c
+++ b/path.c
@@ -816,7 +816,7 @@ const char *enter_repo(const char *path, int strict)
 			if (!newpath)
 				return NULL;
 			strbuf_attach(&used_path, newpath, strlen(newpath),
-				      strlen(newpath));
+				      strlen(newpath) + 1);
 		}
 		for (i = 0; suffix[i]; i++) {
 			struct stat st;
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 561c33ac8a..76bb2ef490 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1514,7 +1514,7 @@ static int commit_ref(struct ref_lock *lock)
 		size_t len = strlen(path);
 		struct strbuf sb_path = STRBUF_INIT;
 
-		strbuf_attach(&sb_path, path, len, len);
+		strbuf_attach(&sb_path, path, len, len + 1);
 
 		/*
 		 * If this fails, commit_lock_file() will also fail
diff --git a/trailer.c b/trailer.c
index 0c414f2fed..135f71aef1 100644
--- a/trailer.c
+++ b/trailer.c
@@ -1095,7 +1095,8 @@ void trailer_info_get(struct trailer_info *info, const char *str,
 	for (ptr = trailer_lines; *ptr; ptr++) {
 		if (last && isspace((*ptr)->buf[0])) {
 			struct strbuf sb = STRBUF_INIT;
-			strbuf_attach(&sb, *last, strlen(*last), strlen(*last));
+			strbuf_attach(&sb, *last, strlen(*last),
+				      strlen(*last) + 1);
 			strbuf_addbuf(&sb, *ptr);
 			*last = strbuf_detach(&sb, NULL);
 			continue;
-- 
2.26.1