On 29/07/19 3:40 AM, Pratyush Yadav wrote:
Hi Brian,
On 29/07/19 3:06 AM, brian m. carlson wrote:
On 2019-07-28 at 15:17:26, Pratyush Yadav wrote:
If any changes are made to the tree while git-gui is open, the user has
to manually rescan to see those changes in the gui. With this change, a
rescan will be performed whenever the window comes in focus, removing
the need for manual rescans in most cases. A manual rescan will still be
needed when something makes changes to the tree while git-gui is still
in focus.
I don't use git-gui, so I have no opinion on this change either way, but
I do have some questions.
What exactly is involved in a rescan? Is it potentially expensive? If
so, it might be better to leave it explicit, since people can
accidentally give focus to the wrong window (bad click, focus follows
mouse, etc.).
The function is not documented, and I only started spelunking the code a
couple days back, so I'll try to answer with what I know. It might not
be the full picture.
Running git-gui --trace, these commands are executed during a rescan:
/usr/lib/git-core/git-rev-parse --verify HEAD
/usr/lib/git-core/git-update-index -q --unmerged --ignore-missing --refresh
Since I'm not too familiar with the details of these, I'll let you be
the judge on how expensive these operations are. But I'll add that
rescans are pretty fast on my relatively slow hard disk.
Is there ever a situation in which someone might want to see the old
state? For example, would a rescan change the active commit shown?
Someone might be looking at a particular commit message or object ID for
the current commit; would this interfere with that?
At least in my workflow, there is no such situation. I use git-gui to
look at uncommitted changes, and stage and commit them. To look at older
commits, I use gitk. And from what I understand, git-gui is not designed
to browse old commits. In the options menu, it simply opens gitk if you
click "Visualise master's history". There is no history browsing in
git-gui itself.
Yes, a rescan will remove the old commit and will show the latest
changes. This includes the old diff that was there before it was
committed or removed from outside of git-gui. So this change will
certainly interfere with the old state.
To add to this, not rescanning has unwanted side effects too. Say you
stage a file, and just as you are about to commit you suddenly remember
one small thing you forgot. So you add that change, and jump back into
git-gui. It shows your file as staged, and the unstaged changes section
is empty. So you commit the change. Hit refresh and your last minute
change didn't make it in the commit, even though the unstaged changes
list was empty. This can cause some confusion, especially among newcomers.
From my perspective, there is more to gain from auto rescanning than
there is to lose.
diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index 6de74ce639..8ca2033dc8 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -3849,6 +3849,7 @@ if {[is_enabled transport]} {
}
bind . <Key-F5> ui_do_rescan
+bind . <FocusIn> do_rescan
What's the difference between these two? Why are we using do_rescan
instead of ui_do_rescan?
ui_do_rescan changes the focus to the first diff. It is executed when
you press F5 or choose Rescan from the menu. do_rescan does not do that.
Resetting to first diff on focus change will get annoying when you are
in the middle of looking at some other file. do_rescan just updates the
software state without changing what file you are looking at or where in
that file you are looking at.
bind . <$M1B-Key-r> ui_do_rescan
bind . <$M1B-Key-R> ui_do_rescan
bind . <$M1B-Key-s> do_signoff
The answers to a lot of these questions can go in your commit message to
help reviewers and future readers understand your change better.
I'm never too sure what I should put in the commit message, so I took
the conservative route. I'll add more details in the v2 patch.
--
Regards,
Pratyush Yadav
