# "git diff-files" command reports differences that don't exist 5 messages from 2021-03-05 to 2021-03-05. Participants: Michael Brown, Junio C Hamano, Eric Sunshine. Thread: https://gitlist.dev/t/55264 ## Michael Brown, 2021-03-05 19:28 Subject: "git diff-files" command reports differences that don't exist Message-ID: <4210f5f1-dd7e-f425-6ab2-e220a33e82bf@discourse.org> URL: https://gitlist.dev/e/4210f5f1-dd7e-f425-6ab2-e220a33e82bf%40discourse.org ``` What did you do before the bug happened? (Steps to reproduce your issue) 1. Be in any existing repository in a clean state (I tested with 2 existing    repositories and 1 completely fresh) 1. run `git diff-files`, see no output 1. touch an existing file: `touch a` 1. run `git diff-files` What did you expect to happen? (Expected behavior) `git diff-files` should show no output What happened instead? (Actual behavior) `git diff-files` reported a difference on the touched file. What's different between what you expected and what actually happened? git reports a difference where none exists Anything else you want to add: This difference vanished after running other commands (e.g. `git diff`). A complete reproduction using docker is below: $ docker run -it --rm debian:latest root@d24ec0793bdf:/# apt update && apt -y install git … root@d24ec0793bdf:/# mkdir ~/new-repo root@d24ec0793bdf:/# cd ~/new-repo root@d24ec0793bdf:~/new-repo# git init Initialized empty Git repository in /root/new-repo/.git/ root@d24ec0793bdf:~/new-repo# touch a root@d24ec0793bdf:~/new-repo# git add a root@d24ec0793bdf:~/new-repo# git config --global user.email 'user@example.net' root@d24ec0793bdf:~/new-repo# git config --global user.name 'Example User' root@d24ec0793bdf:~/new-repo# git commit -m 'initial' [master (root-commit) 791011f] initial  1 file changed, 0 insertions(+), 0 deletions(-)  create mode 100644 a root@d24ec0793bdf:~/new-repo# git diff-files root@d24ec0793bdf:~/new-repo# touch a root@d24ec0793bdf:~/new-repo# git diff-files :100644 100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0000000000000000000000000000000000000000 M    a root@d24ec0793bdf:~/new-repo# git diff root@d24ec0793bdf:~/new-repo# git diff-files root@d24ec0793bdf:~/new-repo# git --version git version 2.20.1 [System Info] git version: git version 2.30.1 cpu: x86_64 no commit associated with this build sizeof-long: 8 sizeof-size_t: 8 shell-path: /bin/sh uname: Linux 5.11.1-arch1-1 #1 SMP PREEMPT Tue, 23 Feb 2021 14:05:30 +0000 x86_64 compiler info: gnuc: 10.2 libc info: glibc: 2.33 $SHELL (typically, interactive shell): /bin/bash This same behaviour was also found in: * 2.20.1 * 2.25.1 [Enabled Hooks] (none) -- Michael Brown Civilized Discourse Construction Kit, Inc. https://www.discourse.org/ ``` ## Junio C Hamano, 2021-03-05 21:49 Subject: Re: "git diff-files" command reports differences that don't exist Message-ID: URL: https://gitlist.dev/e/xmqqa6rh9sph.fsf%40gitster.c.googlers.com In-Reply-To: <4210f5f1-dd7e-f425-6ab2-e220a33e82bf@discourse.org> ``` Michael Brown writes: > What did you do before the bug happened? (Steps to reproduce your issue) > > 1. Be in any existing repository in a clean state (I tested with 2 existing > repositories and 1 completely fresh) > 1. run `git diff-files`, see no output > 1. touch an existing file: `touch a` > 1. run `git diff-files` This is totally expected behaviour. In general when you are working with plumbing commands like diff-files and diff-index, you are expected to do "update-index --refresh" upfront. A plumbing command "git diff" has an equivalent of "update-index --refresh" built into it, but the plumbing commands are designed to be used in scripts, and in order to allow scripting programmers to avoid making unnecessary "update-index --refresh", e.g. git update-index --refresh git diff-files | use diff-files output git diff-index | use diff-index output they leave it the responsibility of the calling script (or the end user who directly use them from the command line) to refresh the cached stat information as necessary. ``` ## Eric Sunshine, 2021-03-05 22:18 Subject: Re: "git diff-files" command reports differences that don't exist Message-ID: URL: https://gitlist.dev/e/CAPig%2BcSRKJUhwMagx_h21pJbBiX9paA5cvDbudDNcRVea6g3Mg%40mail.gmail.com In-Reply-To: ``` On Fri, Mar 5, 2021 at 4:50 PM Junio C Hamano wrote: > This is totally expected behaviour. In general when you are working > with plumbing commands like diff-files and diff-index, you are > expected to do "update-index --refresh" upfront. > > A plumbing command "git diff" has an equivalent of "update-index > --refresh" built into it, but the plumbing commands are designed > to be used in scripts, and in order to allow scripting programmers > to avoid making unnecessary "update-index --refresh", e.g. Did you mean: A porcelain command "git diff" has an equivalent... ? ``` ## Michael Brown, 2021-03-05 22:20 Subject: Re: "git diff-files" command reports differences that don't exist Message-ID: URL: https://gitlist.dev/e/b3774f98-d2aa-3ae2-2aa5-c80339684c50%40discourse.org In-Reply-To: ``` On 2021-03-05 4:49 p.m., Junio C Hamano wrote: > This is totally expected behaviour. In general when you are working > with plumbing commands like diff-files and diff-index, you are > expected to do "update-index --refresh" upfront. Thanks. I wondered if since it was a plumbing command there might have been something I was missing but didn't know where to look. Cheers. -- Michael Brown Civilized Discourse Construction Kit, Inc. https://www.discourse.org/ ``` ## Junio C Hamano, 2021-03-05 22:28 Subject: Re: "git diff-files" command reports differences that don't exist Message-ID: URL: https://gitlist.dev/e/xmqq1rct9qwh.fsf%40gitster.c.googlers.com In-Reply-To: ``` Eric Sunshine writes: > On Fri, Mar 5, 2021 at 4:50 PM Junio C Hamano wrote: >> This is totally expected behaviour. In general when you are working >> with plumbing commands like diff-files and diff-index, you are >> expected to do "update-index --refresh" upfront. >> >> A plumbing command "git diff" has an equivalent of "update-index >> --refresh" built into it, but the plumbing commands are designed >> to be used in scripts, and in order to allow scripting programmers >> to avoid making unnecessary "update-index --refresh", e.g. > > Did you mean: > > A porcelain command "git diff" has an equivalent... Yes. ```