diff mbox series

mergetool(vimdiff): allow paths to contain spaces again

Message ID pull.1287.git.1657726969774.gitgitgadget@gmail.com (mailing list archive)
State Superseded
Headers show
Series mergetool(vimdiff): allow paths to contain spaces again | expand

Commit Message

Johannes Schindelin July 13, 2022, 3:42 p.m. UTC
From: Johannes Schindelin <johannes.schindelin@gmx.de>

In 0041797449d (vimdiff: new implementation with layout support,
2022-03-30), we introduced a completely new implementation of the
`vimdiff` backend for `git mergetool`.

In this implementation, we no longer call `vim` directly but we
accumulate in the variable `FINAL_CMD` an arbitrary number of commands
for `vim` to execute, which necessitates the use of `eval` to split the
commands properly into multiple command-line arguments.

That same `eval` command also needs to pass the paths to `vim`, and
while it looks as if they are quoted correctly, that quoting only
reaches the `eval` instruction and is lost after that, therefore paths
that contain whitespace characters (or other characters that are
interpreted by the POSIX shell) are handled incorrectly.

This is a simple reproducer:

	git init -b main bam-merge-fail
	cd bam-merge-fail
	echo a>"a file.txt"
	git add "a file.txt"
	git commit -m "added 'a file.txt'"
	echo b>"a file.txt"
	git add "a file.txt"
	git commit -m "diverged b 'a file.txt'"
	git checkout -b c HEAD~
	echo c>"a file.txt"
	git add "a file.txt"
	git commit -m "diverged c 'a file.txt'"
	git checkout main
	git merge c
	git mergetool --tool=vimdiff

With Git v2.37.0/v2.37.1, this will open 7 buffers, not four, and not
display the correct contents at all.

To fix this, let's not expand the variables containing the path
parameters before passing them to the `eval` command, but let that
command expand the variables instead.

This fixes https://github.com/git-for-windows/git/issues/3945

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    mergetool(vimdiff): allow paths to contain spaces again
    
    In https://github.com/git-for-windows/git/issues/3945, it was reported
    that as of v2.37.0, git mergetool --tool=vimdiff fails to handle paths
    containing spaces. Let's fix that.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1287%2Fdscho%2Ffix-vimdiff-with-spaces-in-paths-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1287/dscho/fix-vimdiff-with-spaces-in-paths-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1287

 mergetools/vimdiff | 39 +++++++++++++++++++++++++++++++++++----
 1 file changed, 35 insertions(+), 4 deletions(-)


base-commit: 980145f7470e20826ca22d7343494712eda9c81d

Comments

Junio C Hamano July 13, 2022, 4:22 p.m. UTC | #1
"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> To fix this, let's not expand the variables containing the path
> parameters before passing them to the `eval` command, but let that
> command expand the variables instead.

Yup, that is exactly the right approach to fix this kind of
breakage.

Thanks for a clear description of the problem and the solution.

Fernando?  Ack?
Fernando Ramos July 13, 2022, 8:52 p.m. UTC | #2
On 22/07/13 09:22AM, Junio C Hamano wrote:
> Thanks for a clear description of the problem and the solution.
> 
> Fernando?  Ack?

Yes. 100% Ack'ed.

Thanks Johannes for the bug report and the patch!
Junio C Hamano July 13, 2022, 8:54 p.m. UTC | #3
Fernando Ramos <greenfoo@u92.eu> writes:

> On 22/07/13 09:22AM, Junio C Hamano wrote:
>> Thanks for a clear description of the problem and the solution.
>> 
>> Fernando?  Ack?
>
> Yes. 100% Ack'ed.
>
> Thanks Johannes for the bug report and the patch!

Funny that we now seem to fail t7609 mergetool --tool=vimdiff
tests, e.g.

    https://github.com/git/git/actions/runs/2665800752
Junio C Hamano July 13, 2022, 9:08 p.m. UTC | #4
"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

>  	if $base_present
>  	then
> ...
> +	base_present=1

I think s/1/true/ or something is in order, perhaps?

> +	LOCAL='lo cal'
> +	BASE='ba se'
> +	REMOTE="' '"
> +	MERGED='mer ged'
> +	merge_tool_path=record_parameters
> +
> +	merge_cmd vimdiff || at_least_one_ko=true
> +
> +	cat >expect <<-\EOF
> +	-f
> +	-c
> +	echo | split | vertical split | 1b | wincmd l | vertical split | quit | wincmd l | 2b | wincmd j | 3b | tabdo windo diffthis
> +	-c
> +	tabfirst
> +	lo cal
> +	' '
> +	mer ged
> +	EOF
> +
> +	diff -u expect actual || at_least_one_ko=true
> +
>  	if test "$at_least_one_ko" = "true"
>  	then
>  		return 255
>
> base-commit: 980145f7470e20826ca22d7343494712eda9c81d
Fernando Ramos July 13, 2022, 9:33 p.m. UTC | #5
On 22/07/13 02:08PM, Junio C Hamano wrote:
> 
> I think s/1/true/ or something is in order, perhaps?
> 

Yes. I was just looking into that.

For one, as you said, "1" should be "true". That also changes the expected
output.

Then, in addition, the expected output needs to be re-adjusted once again if we
plan to apply this patch on top of the other one from two days ago (the one that
adds the "leftabove" keyword to split subcommands).

After these changes, this is how the original patch from Johannes needs to be
updated:


diff --git a/mergetools/vimdiff b/mergetools/vimdiff
index 56516ae271..3046dcd0dc 100644
--- a/mergetools/vimdiff
+++ b/mergetools/vimdiff
@@ -623,7 +623,7 @@ run_unit_tests () {
 		done
 	}
 
-	base_present=1
+	base_present=true
 	LOCAL='lo cal'
 	BASE='ba se'
 	REMOTE="' '"
@@ -635,10 +635,11 @@ run_unit_tests () {
 	cat >expect <<-\EOF
 	-f
 	-c
-	echo | split | vertical split | 1b | wincmd l | vertical split | quit | wincmd l | 2b | wincmd j | 3b | tabdo windo diffthis
+	echo | -tabnew | leftabove split | leftabove vertical split | 1b | wincmd l | leftabove vertical split | 2b | wincmd l | 3b | wincmd j | 4b | tabnext | -tabnew | leftabove vertical split | 2b | wincmd l | 1b | tabnext | -tabnew | leftabove vertical split | 2b | wincmd l | 3b | tabnext | leftabove vertical split | leftabove split | 1b | wincmd j | leftabove split | 2b | wincmd j | 3b | wincmd l | 4b | tabdo windo diffthis
 	-c
 	tabfirst
 	lo cal
+	ba se
 	' '
 	mer ged
 	EOF
Junio C Hamano July 13, 2022, 9:54 p.m. UTC | #6
Fernando Ramos <greenfoo@u92.eu> writes:

> On 22/07/13 02:08PM, Junio C Hamano wrote:
>> 
>> I think s/1/true/ or something is in order, perhaps?
>> 
>
> Yes. I was just looking into that.
>
> For one, as you said, "1" should be "true". That also changes the expected
> output.

OK, because "1" fails to execute, the expected output Dscho had
(which is for the case without base) would become invalid when we
use "true".

Perhaps we should use "false" instead?  Or do we need to test both?

> Then, in addition, the expected output needs to be re-adjusted once again if we
> plan to apply this patch on top of the other one from two days ago (the one that
> adds the "leftabove" keyword to split subcommands).

> After these changes, this is how the original patch from Johannes needs to be
> updated:
>
>
> diff --git a/mergetools/vimdiff b/mergetools/vimdiff
> index 56516ae271..3046dcd0dc 100644
> --- a/mergetools/vimdiff
> +++ b/mergetools/vimdiff
> @@ -623,7 +623,7 @@ run_unit_tests () {
>  		done
>  	}
>  
> -	base_present=1
> +	base_present=true
>  	LOCAL='lo cal'
>  	BASE='ba se'
>  	REMOTE="' '"
> @@ -635,10 +635,11 @@ run_unit_tests () {
>  	cat >expect <<-\EOF
>  	-f
>  	-c
> -	echo | split | vertical split | 1b | wincmd l | vertical split | quit | wincmd l | 2b | wincmd j | 3b | tabdo windo diffthis
> +	echo | -tabnew | leftabove split | leftabove vertical split | 1b | wincmd l | leftabove vertical split | 2b | wincmd l | 3b | wincmd j | 4b | tabnext | -tabnew | leftabove vertical split | 2b | wincmd l | 1b | tabnext | -tabnew | leftabove vertical split | 2b | wincmd l | 3b | tabnext | leftabove vertical split | leftabove split | 1b | wincmd j | leftabove split | 2b | wincmd j | 3b | wincmd l | 4b | tabdo windo diffthis
>  	-c
>  	tabfirst
>  	lo cal
> +	ba se
>  	' '
>  	mer ged
>  	EOF
Junio C Hamano July 13, 2022, 10:06 p.m. UTC | #7
Junio C Hamano <gitster@pobox.com> writes:

>> For one, as you said, "1" should be "true". That also changes the expected
>> output.
>
> OK, because "1" fails to execute, the expected output Dscho had
> (which is for the case without base) would become invalid when we
> use "true".
>
> Perhaps we should use "false" instead?  Or do we need to test both?

How confident are you with the "leftabove" stuff?  Is it solid
enough that it is safe to assume that we can queue this fix on top
of it?

This is how it would look like on top of the "leftabove" topic.

 mergetools/vimdiff | 39 +++++++++++++++++++++++++++++++++++----
 1 file changed, 35 insertions(+), 4 deletions(-)

diff --git c/mergetools/vimdiff w/mergetools/vimdiff
index b045b10fd7..f770b8fe24 100644
--- c/mergetools/vimdiff
+++ w/mergetools/vimdiff
@@ -414,8 +414,8 @@ merge_cmd () {
 
 	if $base_present
 	then
-		eval "$merge_tool_path" \
-			-f "$FINAL_CMD" "$LOCAL" "$BASE" "$REMOTE" "$MERGED"
+		eval '"$merge_tool_path"' \
+			-f "$FINAL_CMD" '"$LOCAL"' '"$BASE"' '"$REMOTE"' '"$MERGED"'
 	else
 		# If there is no BASE (example: a merge conflict in a new file
 		# with the same name created in both braches which didn't exist
@@ -424,8 +424,8 @@ merge_cmd () {
 		FINAL_CMD=$(echo "$FINAL_CMD" | \
 			sed -e 's:2b:quit:g' -e 's:3b:2b:g' -e 's:4b:3b:g')
 
-		eval "$merge_tool_path" \
-			-f "$FINAL_CMD" "$LOCAL" "$REMOTE" "$MERGED"
+		eval '"$merge_tool_path"' \
+			-f "$FINAL_CMD" '"$LOCAL"' '"$REMOTE"' '"$MERGED"'
 	fi
 
 	ret="$?"
@@ -614,6 +614,37 @@ run_unit_tests () {
 		fi
 	done
 
+	# verify that `merge_cmd` handles paths with spaces
+	record_parameters () {
+		>actual
+		for arg
+		do
+			echo "$arg" >>actual
+		done
+	}
+
+	base_present=false
+	LOCAL='lo cal'
+	BASE='ba se'
+	REMOTE="' '"
+	MERGED='mer ged'
+	merge_tool_path=record_parameters
+
+	merge_cmd vimdiff || at_least_one_ko=true
+
+	cat >expect <<-\EOF
+	-f
+	-c
+	echo | leftabove split | leftabove vertical split | 1b | wincmd l | leftabove vertical split | quit | wincmd l | 2b | wincmd j | 3b | tabdo windo diffthis
+	-c
+	tabfirst
+	lo cal
+	' '
+	mer ged
+	EOF
+
+	diff -u expect actual || at_least_one_ko=true
+
 	if test "$at_least_one_ko" = "true"
 	then
 		return 255
Fernando Ramos July 13, 2022, 10:22 p.m. UTC | #8
On 22/07/13 02:54PM, Junio C Hamano wrote:
> 
> OK, because "1" fails to execute, the expected output Dscho had
> (which is for the case without base) would become invalid when we
> use "true".
> 
> Perhaps we should use "false" instead?  Or do we need to test both?
> 
I think testing both is not really needed as the unit test is just making sure
that filenames with spaces are processed correctly.  Whatever comes before
(which changes depending on the value of "base_present") doesn't really matter
as long as there is something.

If we have to select one ("true" or "false") using "true" seems more practical,
as that way the BASE file is also included, and thus an extra argument is
tested.
Fernando Ramos July 13, 2022, 10:28 p.m. UTC | #9
On 22/07/13 03:06PM, Junio C Hamano wrote:
>
> How confident are you with the "leftabove" stuff?  Is it solid
> enough that it is safe to assume that we can queue this fix on top
> of it?
> 
I would say yes. I have been testing it since without problems.

But it is also true that the "leftabove" patch fixes a corner case that can wait
until the next release.

I will keep testing it in any case and let you know if I find a case where it
doesn't work.
Junio C Hamano July 13, 2022, 10:33 p.m. UTC | #10
Fernando Ramos <greenfoo@u92.eu> writes:

> On 22/07/13 02:54PM, Junio C Hamano wrote:
>> 
>> OK, because "1" fails to execute, the expected output Dscho had
>> (which is for the case without base) would become invalid when we
>> use "true".
>> 
>> Perhaps we should use "false" instead?  Or do we need to test both?
>> 
> I think testing both is not really needed as the unit test is just making sure
> that filenames with spaces are processed correctly.  Whatever comes before
> (which changes depending on the value of "base_present") doesn't really matter
> as long as there is something.

As the quoting glitch are distributed on both sides

	if $base_present
	then
		eval "$merge_tool_path" \
			-f "$FINAL_CMD" "$LOCAL" "$BASE" "$REMOTE" "$MERGED"
	else
		# If there is no BASE (example: a merge conflict in a new file
		# with the same name created in both braches which didn't exist
		# before), close all BASE windows using vim's "quit" command

		FINAL_CMD=$(echo "$FINAL_CMD" | \
			sed -e 's:2b:quit:g' -e 's:3b:2b:g' -e 's:4b:3b:g')

		eval "$merge_tool_path" \
			-f "$FINAL_CMD" "$LOCAL" "$REMOTE" "$MERGED"
	fi

I suspect you can fix only one, and carefully choose which side to
test, and leave the other side broken ;-)

In any case, to minimize disruption to Dscho's patch, I replaced the
"1" with "false" (which will make his patch pass the new test
without other stuff) and tweak its merge into 'seen' to adjust for
the "leftabove" topic.

Thanks.
diff mbox series

Patch

diff --git a/mergetools/vimdiff b/mergetools/vimdiff
index 461a89b6f98..59e1e2f5ca5 100644
--- a/mergetools/vimdiff
+++ b/mergetools/vimdiff
@@ -414,8 +414,8 @@  merge_cmd () {
 
 	if $base_present
 	then
-		eval "$merge_tool_path" \
-			-f "$FINAL_CMD" "$LOCAL" "$BASE" "$REMOTE" "$MERGED"
+		eval '"$merge_tool_path"' \
+			-f "$FINAL_CMD" '"$LOCAL"' '"$BASE"' '"$REMOTE"' '"$MERGED"'
 	else
 		# If there is no BASE (example: a merge conflict in a new file
 		# with the same name created in both braches which didn't exist
@@ -424,8 +424,8 @@  merge_cmd () {
 		FINAL_CMD=$(echo "$FINAL_CMD" | \
 			sed -e 's:2b:quit:g' -e 's:3b:2b:g' -e 's:4b:3b:g')
 
-		eval "$merge_tool_path" \
-			-f "$FINAL_CMD" "$LOCAL" "$REMOTE" "$MERGED"
+		eval '"$merge_tool_path"' \
+			-f "$FINAL_CMD" '"$LOCAL"' '"$REMOTE"' '"$MERGED"'
 	fi
 
 	ret="$?"
@@ -614,6 +614,37 @@  run_unit_tests () {
 		fi
 	done
 
+	# verify that `merge_cmd` handles paths with spaces
+	record_parameters () {
+		>actual
+		for arg
+		do
+			echo "$arg" >>actual
+		done
+	}
+
+	base_present=1
+	LOCAL='lo cal'
+	BASE='ba se'
+	REMOTE="' '"
+	MERGED='mer ged'
+	merge_tool_path=record_parameters
+
+	merge_cmd vimdiff || at_least_one_ko=true
+
+	cat >expect <<-\EOF
+	-f
+	-c
+	echo | split | vertical split | 1b | wincmd l | vertical split | quit | wincmd l | 2b | wincmd j | 3b | tabdo windo diffthis
+	-c
+	tabfirst
+	lo cal
+	' '
+	mer ged
+	EOF
+
+	diff -u expect actual || at_least_one_ko=true
+
 	if test "$at_least_one_ko" = "true"
 	then
 		return 255