From 48c171d927407132875283db3afb05b08b98a078 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Thu, 28 Mar 2024 19:02:30 +0100 Subject: [PATCH] find_hook(): refactor the `STRIP_EXTENSION` logic When looking for a hook and not finding one, and when `STRIP_EXTENSION` is available (read: if we're on Windows and `.exe` is the required extension for executable programs), we want to look also for a hook with that extension. Previously, we added that handling into the conditional block that was meant to handle when no hook was found (possibly providing some advice for the user's benefit). If the hook with that file extension was found, we'd return early from that function instead of writing out said advice, of course. However, we're about to introduce a safety valve to prevent hooks from being run during a clone, to reduce the attack surface of bugs that allow writing files to be written into arbitrary locations. To prepare for that, refactor the logic to avoid the early return, by separating the `STRIP_EXTENSION` handling from the conditional block handling the case when no hook was found. This commit is best viewed with `--patience`. Signed-off-by: Johannes Schindelin --- hook.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/hook.c b/hook.c index a4fa1031f2..22b274b60b 100644 --- a/hook.c +++ b/hook.c @@ -7,20 +7,24 @@ const char *find_hook(const char *name) { static struct strbuf path = STRBUF_INIT; + int found_hook; + strbuf_reset(&path); strbuf_git_path(&path, "hooks/%s", name); - if (access(path.buf, X_OK) < 0) { + found_hook = access(path.buf, X_OK) >= 0; +#ifdef STRIP_EXTENSION + if (!found_hook) { int err = errno; -#ifdef STRIP_EXTENSION strbuf_addstr(&path, STRIP_EXTENSION); - if (access(path.buf, X_OK) >= 0) - return path.buf; - if (errno == EACCES) - err = errno; + found_hook = access(path.buf, X_OK) >= 0; + if (!found_hook) + errno = err; + } #endif - if (err == EACCES && advice_enabled(ADVICE_IGNORED_HOOK)) { + if (!found_hook) { + if (errno == EACCES && advice_enabled(ADVICE_IGNORED_HOOK)) { static struct string_list advise_given = STRING_LIST_INIT_DUP; if (!string_list_lookup(&advise_given, name)) {