Subject: Re: [PATCH v3 3/4] t7800: modernize tests

From: Johannes Sixt <[email-masked]>
Date: Fri, 22 Mar 2013 08:13:46 +0100

Am 3/21/2013 8:41, schrieb Johannes Sixt:
> Am 3/20/2013 23:59, schrieb David Aguilar:
>> I started digging in and the @worktree_files (aka @worktree above)
>> is populated from the output of "git diff --raw ...".
>>
>> Seeing the "output" filename in "diff --raw" implies that one of the
>> tests added "output" to the index somehow.  I do not see that
>> happening anywhere, though, so I do not know how it would end up in
>> the @worktree array if it is not reported by "diff --raw".
>>
>>
>> My current understanding of how it could possibly be open twice:
>>
>> 1. via the >output redirect
>> 2. via the copy() perl code which is fed by @worktree
>>
>> So I'm confused.  Why would we get different results on Windows?
> 
> I tracked down the difference between Windows and Linux, and it is...
> 
> 	for my $file (@worktree) {
> 		next if $symlinks && -l "$b/$file";
> 
> ... this line in sub dir_diff. On Linux, we take the short-cut, but on
> Windows we proceed through the rest of the loop,

And that is likely by design. From the docs:

--symlinks
--no-symlinks

    git difftool's default behavior is create symlinks to the working
    tree when run in --dir-diff mode.

    Specifying `--no-symlinks` instructs 'git difftool' to create
    copies instead.  `--no-symlinks` is the default on Windows.

And indeed, we have this initialization:

	my %opts = (
		...
		symlinks => $^O ne 'cygwin' &&
				$^O ne 'MSWin32' && $^O ne 'msys',
		...
	);

Can the --dir-diff tests case pass on Cygwin when neither --symlinks nor
--no-symlinks is passed?

Perhaps the right solution is this:

diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index c6d6b1c..19238f6 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -328,14 +328,16 @@ test_expect_success PERL 'setup change in subdirectory' '
 	git commit -m "modified both"
 '
 
-test_expect_success PERL 'difftool -d' '
-	git difftool -d --extcmd ls branch >output &&
+# passing --symlinks helps Cygwin, which defaults to --no-symlinks
+
+test_expect_success PERL,SYMLINKS 'difftool -d' '
+	git difftool -d --symlinks --extcmd ls branch >output &&
 	stdin_contains sub <output &&
 	stdin_contains file <output
 '
 
-test_expect_success PERL 'difftool --dir-diff' '
-	git difftool --dir-diff --extcmd ls branch >output &&
+test_expect_success PERL,SYMLINKS 'difftool --dir-diff' '
+	git difftool --dir-diff --symlinks --extcmd ls branch >output &&
 	stdin_contains sub <output &&
 	stdin_contains file <output
 '
@@ -362,16 +364,16 @@ test_expect_success PERL,SYMLINKS 'difftool --dir-diff --symlink without unstage
 	test_cmp actual expect
 '
 
-test_expect_success PERL 'difftool --dir-diff ignores --prompt' '
-	git difftool --dir-diff --prompt --extcmd ls branch >output &&
+test_expect_success PERL,SYMLINKS 'difftool --dir-diff ignores --prompt' '
+	git difftool --dir-diff --symlinks --prompt --extcmd ls branch >output &&
 	stdin_contains sub <output &&
 	stdin_contains file <output
 '
 
-test_expect_success PERL 'difftool --dir-diff from subdirectory' '
+test_expect_success PERL,SYMLINKS 'difftool --dir-diff from subdirectory' '
 	(
 		cd sub &&
-		git difftool --dir-diff --extcmd ls branch >output &&
+		git difftool --dir-diff --symlinks --extcmd ls branch >output &&
 		stdin_contains sub <output &&
 		stdin_contains file <output
 	)

(Only tested on MinGW, which skips the tests.) I leave it to you
to write --no-symlinks tests.

-- Hannes