Fix export_marks() error handling.

diff --git a/git-difftool.perl b/git-difftool.perl
index 8857ac8a4cfa733c1158cdb9a0d3e453bd8d235c..ba5e60a45e2c4a8b54e6a58e656b3978dcb45633 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -2,9 +2,12 @@
 # Copyright (c) 2009 David Aguilar
 #
 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
-# git-difftool--helper script.  This script exports
-# GIT_EXTERNAL_DIFF and GIT_PAGER for use by git, and
-# GIT_DIFFTOOL_NO_PROMPT and GIT_DIFF_TOOL for use by git-difftool--helper.
+# git-difftool--helper script.
+#
+# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
+# GIT_DIFFTOOL_NO_PROMPT, GIT_DIFFTOOL_PROMPT, and GIT_DIFF_TOOL
+# are exported for use by git-difftool--helper.
+#
 # Any arguments that are unknown to this script are forwarded to 'git diff'.
 
 use strict;
@@ -62,6 +65,12 @@ sub generate_command
                }
                if ($arg eq '-y' || $arg eq '--no-prompt') {
                        $ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
+                       delete $ENV{GIT_DIFFTOOL_PROMPT};
+                       next;
+               }
+               if ($arg eq '--prompt') {
+                       $ENV{GIT_DIFFTOOL_PROMPT} = 'true';
+                       delete $ENV{GIT_DIFFTOOL_NO_PROMPT};
                        next;
                }
                if ($arg eq '-h' || $arg eq '--help') {
@@ -73,4 +82,11 @@ sub generate_command
 }
 
 setup_environment();
-exec(generate_command());
+
+# ActiveState Perl for Win32 does not implement POSIX semantics of
+# exec* system call. It just spawns the given executable and finishes
+# the starting program, exiting with code 0.
+# system will at least catch the errors returned by git diff,
+# allowing the caller of git difftool better handling of failures.
+my $rc = system(generate_command());
+exit($rc | ($rc >> 8));