Unexpected behavior when parsing output of `git show` run on `stash` reflog-style refs about ydiff

[ymattw]

Thank you for giving those very useful information. I am closing this issue because it's intended behavior.

[ymattw]

The command `git show stash@{1}` outputs in diffstat format not unified diff (patch) format. If I remembered correctly, `git stash show -p stash@{1} | cdiff -s` should work. You may want to make an alias for it if you use it frequently.

…

On Fri, 7 Jul 2017 at 19:14 Peter Henry ***@***.***> wrote: Probably not a bug; just me not being a cdiff wizard yet. Haven't been able to figure out how to get it working yet, so help is appreciated! Summary Running something like this: git show stash@{1} | cdiff -s results in one column of mostly-cyan text that seems to be missing sections. I expected it to behave similarly to git show 4e2fc7b | cdiff -s, which results in the whole diff rendered in two columns of diff-colored text. I've tried several different stash indexes as well as just git show stash and all of them behaved the same way. To Reproduce - Operating system: Ubuntu 14.04 (I know, I know) - Version of cdiff: 1.0 - Installation method: iirc, pip install cdiff at the system level (binary is in /usr/local/bin/cdiff) I dumped the results of the two git-show commands above to two files described below. Create those files, then run the following: cat git-show-stash.txt | cdiff -s # unexpected behavior cat git-show-sha.txt | cdiff -s # expected behavior Files *git-show-stash.txt* commit 7c931ec949fd936ebdc43cb7cff58a6dabe88bec [0/5] Merge: adc3783 a2a6bd5 Author: Firstname Lastname ***@***.***> Date: Wed Jul 5 15:46:59 2017 -0500 WIP on zone_delta_processing: adc3783 fix "no module named PythonMagick" error by switching to pgmagick diff --cc rtls/urls.py index 3ea1a0b,3ea1a0b..1cc7364--- a/rtls/urls.py+++ b/rtls/urls.py@@@ -49,6 -49,6 +49,11 @@@ urlpatterns = views.api_disassociate_holder, name='api_disassociate_holder', ),++ url( # receives zone delta bundles, determines what actions to take (if any)++ r'^(?i)api/triage-deltas/zone?$',++ views.api_triage_zone_deltas,++ name='api_triage_zone_deltas',++ ), # --------- Map URLS ---------diff --cc rtls/views.py index 694ae27,694ae27..45e874c--- a/rtls/views.py+++ b/rtls/views.py@@@ -6,6 -6,6 +6,7 @@@ from django.core.exceptions import Mult from django.core.mail import EmailMessage, send_mail from django.http import HttpResponse, HttpResponseNotFound, JsonResponse from django.shortcuts import render, render_to_response, get_object_or_404++from django.views.decorators.csrf import csrf_exempt from contacts.models import Person, Location from mosaiq.models import (@@@ -75,6 -75,6 +76,16 @@@ def api_potential_holder_list(request) )) ***@***.***_exempt++def api_triage_zone_deltas(request):++ '''Receives a bundle of zone delta objects as a POST and determines what++ actions need to be taken because of them, if any.'''++ # print 'REMOTE_HOST', request.META['REMOTE_HOST']++ # print 'HTTP_HOST', request.META['HTTP_HOST']++ print '\nContents of POST:', request.POST, '\n'++ return HttpResponse(status=200)++++ def association_node_list(request): return render(request, 'rtls/association_node_list.html', { 'registration_nodes': Node.objects.filter(topic='tag_reg') *git-show-sha.txt* commit 4e2fc7b5cb84a459f82e2f913a97a0b49f6e8b0d [0/5] Author: Firstname Lastname ***@***.***> Date: Fri Jun 30 11:47:52 2017 -0500 document associate/disassociate urls diff --git a/rtls/urls.py b/rtls/urls.py index 378b0a7..3ea1a0b 100644--- a/rtls/urls.py+++ b/rtls/urls.py@@ -39,12 +39,12 @@ urlpatterns = [ views.api_potential_holder_list, name='api_potential_holder_list', ),- url(+ url( # used to associate a tag and a holder r'^(?i)api/association/associate/?$', views.api_associate, name='api_associate', ),- url(+ url( # used to disassociate a holder from any tag it may be associated with r'^(?i)api/association/disassociate/?$', views.api_disassociate_holder, name='api_disassociate_holder', — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#65>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABV4j9xtiZWn-9Yq6XAX1f6AuqmOus4sks5sLmdmgaJpZM4ORNMD> .

[mosbasik]

Thank you, that does the job. Sorry it's taken a while to get back to you.

Spent a while reading through the git-diff, git-stash and git-show docs trying to suss out what the default formats are for various cases and what options they support. Learned quite a few things but there's definitely some dark corners still.

In case anyone else finds this with the same questions I had:

git stash show <ref>

This command is built on top of git diff and can take any of its options. By default, it does output a diffstat (NB: this is probably what you meant in your first line instead of git show <ref>.) But it can take --patch, which makes it output a diff in patch format, which cdiff can parse (as you suggested).

git show <object>

This is a multipurpose command to display several kinds of things.

• When <object> is a non-merge commit, the default output is in two parts: 1) a header with the commit author/date/message and 2) a diff body generated by a normal git diff (you can see this by running, e.g., diff -us <(git show) <(git diff HEAD~1 HEAD) as long as the last commit wasn't a merge). cdiff can parse the output for this case just fine.

• When <object> is a merge commit, by default git show uses git diff's --cc option to generate a combined diff. cdiff can't parse the output for this case.

• When <object> is a stash ref, it's always going to be a merge commit, because of the way stashes are stored.

However, if the -m option is used (git show -m <object>), multiple single diffs are generated instead, and cdiff can parse those. (Though in the case of stashes, you'll basically be seeing two copies of the same diff)

So both of these work:

git stash show -p stash@{1} | cdiff -s    # longer, one diff
git show -m stash@{1} | cdiff -s          # shorter, two diffs