[PATCH 10/9 v4] difftool: fix regression in '--prompt' options

[Tim Henigan <tim.henigan@gmail.com>]

When difftool was changed to use Getopt::Long, it changed the way
that the '--prompt' and '--no-prompt' options were handled. The
expected behavior is that the two options may be given any number
of times. The last option given "wins".

For example, if a user sets "[alias] mdt = difftool --prompt", the
following must still run without error:

$ git mdt --no-prompt

The changes made during the switch to Getopt::Long broke this
behavior. This commit teaches difftool to handle them properly
again.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
---

This replaces 10/9 in v3 of the series.

Changes in v4:
  - '--prompt' and '--no-prompt' may be used together again.
  - Removed changes made to t7800.  The old test now passes.


 git-difftool.perl |   32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index 9f0f9a9..41c6557 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -22,6 +22,7 @@ use File::Temp qw(tempdir);
 use Getopt::Long qw(:config pass_through);
 use Git;
 
+my @diffargs;
 my @working_tree;
 
 sub usage
@@ -41,7 +42,7 @@ sub setup_dir_diff
 {
 	# Run the diff; exit immediately if no diff found
 	my $repo = Git->repository();
-	my $diffrtn = $repo->command_oneline(['diff', '--raw', '--no-abbrev', '-z', @ARGV]);
+	my $diffrtn = $repo->command_oneline(['diff', '--raw', '--no-abbrev', '-z', @diffargs]);
 	exit(0) if (length($diffrtn) == 0);
 
 	# Setup temp directories
@@ -131,15 +132,25 @@ sub setup_dir_diff
 
 # parse command-line options. all unrecognized options and arguments
 # are passed through to the 'git diff' command.
-my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $no_prompt, $prompt, $tool_help);
+my ($difftool_cmd, $dirdiff, $extcmd, $gui, $help, $prompt, $tool_help);
 GetOptions('g|gui' => \$gui,
 	'd|dir-diff' => \$dirdiff,
 	'h' => \$help,
-	'prompt' => \$prompt,
 	't|tool:s' => \$difftool_cmd,
 	'tool-help' => \$tool_help,
-	'x|extcmd:s' => \$extcmd,
-	'y|no-prompt' => \$no_prompt);
+	'x|extcmd:s' => \$extcmd);
+
+# the '--prompt' and '--no-prompt' options require special treatment
+# because they may be specified more than once...the last one "wins".
+for (@ARGV) {
+	if (($_ eq "-y") or ($_ eq "--no-prompt")) {
+		$prompt = 0;
+	} elsif ($_ eq "--prompt") {
+		$prompt = 1;
+	} else {
+		push(@diffargs, $_);
+	}
+}
 
 if (defined($help)) {
 	usage(0);
@@ -203,13 +214,14 @@ if (defined($dirdiff)) {
 	}
 } else {
 	if (defined($prompt)) {
-		$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
-	}
-	elsif (defined($no_prompt)) {
-		$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
+		if ($prompt) {
+			$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
+		} else {
+			$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
+		}
 	}
 
 	$ENV{GIT_PAGER} = '';
 	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
-	git_cmd_try { Git::command_noisy(('diff', @ARGV)) } 'exit code %d';
+	git_cmd_try { Git::command_noisy(('diff', @diffargs)) } 'exit code %d';
 }
-- 
1.7.10.rc1.39.gdeb0e