From 71571cd7d61b2e5c90684322b38e60ffadd33448 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20=C3=85gren?= Date: Tue, 30 Oct 2018 09:09:37 +0100 Subject: sequencer: break out of loop explicitly MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It came up in review [1, 2] that this non-idiomatic loop is a bit tricky. When we find a space, we set `len = i`, which gives us the answer we are looking for, but which also breaks out of the loop. It turns out that this loop can confuse compilers as well. My copy of gcc 7.3.0 realizes that we are essentially evaluating `(len + 1) < len` and warns that the behavior is undefined if `len` is `INT_MAX`. (Because the assignment `len = i` is guaranteed to decrease `len`, such undefined behavior is not actually possible.) Rewrite the loop to a more idiomatic variant which doesn't muck with `len` in the loop body. That should help compilers and human readers figure out what is going on here. But do note that we need to update `len` since it is not only used just after this loop (where we could have used `i` directly), but also later in this function. While at it, reduce the scope of `i`. [1] https://public-inbox.org/git/CAPig+cQbG2s-LrAo9+7C7=dXifbWFJ3SzuNa-QePHDk7egK=jg@mail.gmail.com/ [2] https://public-inbox.org/git/CAPig+cRjU6niXpT2FrDWZ0x1HmGf1ojVZj3uk2qXEGe-S7i_HQ@mail.gmail.com/ Helped-by: Eric Sunshine Signed-off-by: Martin Ågren Signed-off-by: Junio C Hamano --- sequencer.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/sequencer.c b/sequencer.c index dc2c58d464..11c5a65a32 100644 --- a/sequencer.c +++ b/sequencer.c @@ -2825,7 +2825,7 @@ static int do_reset(const char *name, int len, struct replay_opts *opts) struct tree_desc desc; struct tree *tree; struct unpack_trees_options unpack_tree_opts; - int ret = 0, i; + int ret = 0; if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) return -1; @@ -2845,10 +2845,13 @@ static int do_reset(const char *name, int len, struct replay_opts *opts) } oidcpy(&oid, &opts->squash_onto); } else { + int i; + /* Determine the length of the label */ for (i = 0; i < len; i++) if (isspace(name[i])) - len = i; + break; + len = i; strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name); if (get_oid(ref_name.buf, &oid) && -- cgit v1.2.3