Re: t7800-difftool.sh failure on pu

Junio C Hamano wrote:

Ramsay Jones [off-list ref] writes:

quoted

The first option is to (effectively) revert commit 0440ed72 ("difftool: replace
system call with Git::command_noisy", 22-03-2012), like so:

-- >8 --

diff --git a/git-difftool.perl b/git-difftool.perl
index e1754ff..49613b1 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl

@@ -237,5 +237,7 @@ if (defined($dirdiff)) {
 
 	$ENV{GIT_PAGER} = '';
 	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
-	git_cmd_try { Git::command_noisy(('diff', @ARGV)) } 'exit code %d';
+	my @command = ('git', 'diff', @ARGV);
+	my $rc = system(@command);
+	exit($rc | ($rc >> 8));
 }
-- 8< --

I would prefer this, regardless of the issue.

Me too! ;-P

I noticed this afternoon (using my isp's web-mail interface) that Tim has
already sent a patch fixing this issue along these lines. [Thanks Tim]

However, just for the record, all three of the platforms I test on failed
in more-or-less the same way. [the exit code on cygwin was 2 (No such File
or Directory) rather than 9.]

Note that the failure occurred (on Linux, cygwin and MinGW) when pu was at
commit e5471b396660313b172e102b50939c9c35d4c637 (v1.7.10-rc2-260-ge5471b3).
However, on Linux, having fetched an updated pu which is now at commit
ae98c9308d3a79f2b22de2f6dae614f700f7ce0c (v1.7.10-rc3-272-gae98c93), then
test t7800 now reliably passes!

[when I say it reliably passes (fails), I mean it passes (fails) each time
on ten consecutive runs.]

I created a diff of git-difftool.perl between these two commits and applied
the patch, in reverse, to effectively revert that file. Having done so, then
t7800 once again reliably fails! Looking at the diff, I have no idea why!
[I've included the diff below, just for completeness.]

ATB,
Ramsay Jones

dt.diff:
-- >8 --

diff --git a/git-difftool.perl b/git-difftool.perl
index e1754ff..78e93a6 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl

@@ -14,14 +14,16 @@
 use 5.008;
 use strict;
 use warnings;
-use File::Basename qw(dirname basename);
+use File::Basename qw(dirname);
 use File::Copy;
+use File::Find;
 use File::stat;
 use File::Path qw(mkpath);
 use File::Temp qw(tempdir);
 use Getopt::Long qw(:config pass_through);
 use Git;
 
+my @tools;
 my @working_tree;
 
 sub usage

@@ -38,17 +40,32 @@ USAGE
 	exit($exitcode);
 }
 
+sub filter_tool_scripts
+{
+	if (-d $_) {
+		if ($_ ne ".") {
+			# Ignore files in subdirectories
+			$File::Find::prune = 1;
+		}
+	} else {
+		if ((-f $_) && ($_ ne "defaults")) {
+			push(@tools, $_);
+		}
+	}
+}
+
 sub print_tool_help
 {
 	my ($cmd, @found, @notfound);
 	my $gitpath = Git::exec_path();
 
-	for (glob "$gitpath/mergetools/*") {
-		my $tool = basename($_);
-		next if ($tool eq "defaults");
+	find(\&filter_tool_scripts, "$gitpath/mergetools");
 
-		$cmd  = '. "$(git --exec-path)/git-mergetool--lib"';
+	foreach my $tool (@tools) {
+		$cmd  = "TOOL_MODE=diff";
+		$cmd .= ' && . "$(git --exec-path)/git-mergetool--lib"';
 		$cmd .= " && get_merge_tool_path $tool >/dev/null 2>&1";
+		$cmd .= " && can_diff >/dev/null 2>&1";
 		if (system('sh', '-c', $cmd) == 0) {
 			push(@found, $tool);
 		} else {

@@ -57,10 +74,10 @@ sub print_tool_help
 	}
 
 	print "'git difftool --tool=<tool>' may be set to one of the following:\n";
-	print "\t$_\n" for (@found);
+	print "\t$_\n" for (sort(@found));
 
 	print "\nThe following tools are valid, but not currently available:\n";
-	print "\t$_\n" for (@notfound);
+	print "\t$_\n" for (sort(@notfound));
 
 	print "\nNOTE: Some of the tools listed above only work in a windowed\n";
 	print "environment. If run in a terminal-only session, they will fail.\n";
-- 8< --