From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id B72CF1F5AE for ; Fri, 11 Jun 2021 13:41:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230450AbhFKNnc (ORCPT ); Fri, 11 Jun 2021 09:43:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229722AbhFKNnV (ORCPT ); Fri, 11 Jun 2021 09:43:21 -0400 Received: from mav.lukeshu.com (mav.lukeshu.com [IPv6:2001:19f0:5c00:8069:5400:ff:fe26:6a86]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7E13C061574 for ; Fri, 11 Jun 2021 06:41:23 -0700 (PDT) Received: from lukeshu-dw-thinkpad (unknown [IPv6:2601:281:8200:42e:527b:9dff:fe2b:180a]) by mav.lukeshu.com (Postfix) with ESMTPSA id 5C3B980590; Fri, 11 Jun 2021 09:41:21 -0400 (EDT) Date: Fri, 11 Jun 2021 07:41:20 -0600 Message-ID: <875yyk7c3j.wl-lukeshu@lukeshu.com> From: Luke Shumaker To: Johannes Schindelin Cc: Luke Shumaker , Johannes Schindelin via GitGitGadget , git@vger.kernel.org, Luke Shumaker Subject: Re: [PATCH 1/2] subtree: fix the GIT_EXEC_PATH sanity check to work on Windows In-Reply-To: References: <87bl8d6xoq.wl-lukeshu@lukeshu.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?ISO-8859-4?Q?Goj=F2?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.2 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Fri, 11 Jun 2021 04:19:17 -0600, Johannes Schindelin wrote: > > Hi Luke, > > On Thu, 10 Jun 2021, Luke Shumaker wrote: > > > On Thu, 10 Jun 2021 03:13:30 -0600, > > Johannes Schindelin via GitGitGadget wrote: > > > -if test -z "$GIT_EXEC_PATH" || test "${PATH#"${GIT_EXEC_PATH}:"}" = "$PATH" || ! test -f "$GIT_EXEC_PATH/git-sh-setup" > > > +if test -z "$GIT_EXEC_PATH" || { > > > + test "${PATH#"${GIT_EXEC_PATH}:"}" = "$PATH" && { > > > + # On Windows, PATH might be Unix-style, GIT_EXEC_PATH not > > > + ! type -p cygpath >/dev/null 2>&1 || > > > + test "${PATH#$(cygpath -au "$GIT_EXEC_PATH"):}" = "$PATH" > > > > Nit: That should have a couple more `"` in it: > > > > test "${PATH#"$(cygpath -au "$GIT_EXEC_PATH"):"}" = "$PATH" > > Are you sure about that? > > $ P='*:hello'; echo "${P#$(echo '*'):}" > hello > > As you can see, there is no problem with that `echo '*'` producing a > wildcard character. > > In any case, neither '*' nor '?' are valid filename characters on Windows, > therefore there is little danger here. In the other email (the reply to Junio), I specified that it's only a problem if the glob isn't self-matching. So * and ? are fine, but [charset] probably isn't. $ P='f[o]o:bar'; echo "${P#$(echo 'f[o]o'):}" f[o]o:bar $ P='f[o]o:bar'; echo "${P#"$(echo 'f[o]o'):"}" bar > To be honest, I was looking more for reviews focusing on > potentially-better solutions, such as looking at the inodes, or even > comparing the contents of `$GIT_EXEC_PATH/git-subtree` and > `${PATH%%:*}/git-subtree`, and complaining if they're not identical. So the check right now is gross, but I don't know what would be better. The point of the check is more to check "is the environment set up the way that `git` sets it up for us", not so much to actually check the filesystem. Plus, it shouldn't actually care if it's installed in `$GIT_EXEC_PATH` or not, it should be totally happy for $GIT_EXEC_PATH/git-subtree to not exist and for git-subtree to be elsewhere in the PATH. So an inode or content check would be wrong. Perhaps checking git-sh-setup instead of git-subtree though... > Those two ideas look a bit ham-handed to me, though, the latter because it > reads the file twice, for _every_ `git subtree` invocation, and the fomer > because there simply is no easy portable way to look at the inode of a > file (stat(1) has different semantics depending whether it is the GNU or > the BSD flavor, and it might not even be present to begin with). `test FILE1 -ef FILE2` checks wether the inode is the same. And it's POSIX, so I'm assuming that it's sufficiently portable, though I haven't actually tested whether things other than Bash implement it. > I was also looking forward to hear whether there are opinions about maybe > dropping this check altogether because there were indications that this > condition is not even common anymore. I think it would be good for it to eventually go away. But having removed the hacks that allowed it to work in broken setups, I have no way of knowing how many people had setups like that unless they tell me now that it's telling them, and if those users are now broken, I don't want them to be *silently* broken. So I think we do need to have the check for a longish period of time. > > But no need to re-roll for just that. > > > > Do we also need to handle the reverse case, where PATH uses > > backslashes but GIT_EXEC_PATH uses forward slashes? > > In Git for Windows, we ensure to use forward slashes in `GIT_EXEC_PATH`. Did you mean to write `PATH` here instead of `GIT_EXEC_PATH`? Because if not, then I'm confused. -- Happy hacking, ~ Luke Shumaker