difftool: add support for --trust-exit-code

Teach difftool to exit when a diff tool returns a non-zero exit
code when either --trust-exit-code is specified or
difftool.trustExitCode is true.

Forward exit codes from invoked diff tools to the caller when
--trust-exit-code is used.

Suggested-by: Adri Farr <14farresa@gmail.com>
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 11887e63a05904d95f7d07d51b818721b33c0b66..333cf6ff91c59fd96b587257ad413268df9a1458 100644 (file)
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -91,6 +91,15 @@ instead.  `--no-symlinks` is the default on Windows.
        the default diff tool will be read from the configured
        `diff.guitool` variable instead of `diff.tool`.
 
+--[no-]trust-exit-code::
+       'git-difftool' invokes a diff tool individually on each file.
+       Errors reported by the diff tool are ignored by default.
+       Use `--trust-exit-code` to make 'git-difftool' exit when an
+       invoked diff tool returns a non-zero exit code.
++
+'git-difftool' will forward the exit code of the invoked tool when
+'--trust-exit-code' is used.
+
 See linkgit:git-diff[1] for the full list of supported options.
 
 CONFIG VARIABLES
@@ -116,6 +125,11 @@ See the `--tool=<tool>` option above for more details.
 difftool.prompt::
        Prompt before each invocation of the diff tool.
 
+difftool.trustExitCode::
+       Exit difftool if the invoked diff tool returns a non-zero exit status.
++
+See the `--trust-exit-code` option above for more details.
+
 SEE ALSO
 --------
 linkgit:git-diff[1]::

diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index aca0413c2840a3097056d6d247aad9438451249e..d4fb6dfe138fffd4d000c7d5aeb7787bea9970f4 100755 (executable)
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -85,6 +85,12 @@ else
        while test $# -gt 6
        do
                launch_merge_tool "$1" "$2" "$5"
+               status=$?
+               if test "$status" != 0 &&
+                       test "$GIT_DIFFTOOL_TRUST_EXIT_CODE" = true
+               then
+                       exit $status
+               fi
                shift 7
        done
 fi

diff --git a/git-difftool.perl b/git-difftool.perl
index 18ca61e8d0493bde9c21ed337043bc72fa5c73a7..9a1054a2bb9d72d10aeb88c6bdf1d47b0fde1a75 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -346,6 +346,7 @@ sub main
                symlinks => $^O ne 'cygwin' &&
                                $^O ne 'MSWin32' && $^O ne 'msys',
                tool_help => undef,
+               trust_exit_code => undef,
        );
        GetOptions('g|gui!' => \$opts{gui},
                'd|dir-diff' => \$opts{dirdiff},
@@ -356,6 +357,8 @@ sub main
                'no-symlinks' => sub { $opts{symlinks} = 0; },
                't|tool:s' => \$opts{difftool_cmd},
                'tool-help' => \$opts{tool_help},
+               'trust-exit-code' => \$opts{trust_exit_code},
+               'no-trust-exit-code' => sub { $opts{trust_exit_code} = 0; },
                'x|extcmd:s' => \$opts{extcmd});
 
        if (defined($opts{help})) {
@@ -387,6 +390,15 @@ sub main
                }
        }
 
+       if (!defined $opts{trust_exit_code}) {
+               $opts{trust_exit_code} = Git::config_bool('difftool.trustExitCode');
+       }
+       if ($opts{trust_exit_code}) {
+               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'true';
+       } else {
+               $ENV{GIT_DIFFTOOL_TRUST_EXIT_CODE} = 'false';
+       }
+
        # In directory diff mode, 'git-difftool--helper' is called once
        # to compare the a/b directories.  In file diff mode, 'git diff'
        # will invoke a separate instance of 'git-difftool--helper' for

diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 9cf5dc9347971438b50e2a23cbb005758106ab5e..69bde7aa288d1deebb7d6204e29f88978d880998 100755 (executable)
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -76,6 +76,49 @@ test_expect_success PERL 'difftool forwards arguments to diff' '
        rm for-diff
 '
 
+test_expect_success PERL 'difftool ignores exit code' '
+       test_config difftool.error.cmd false &&
+       git difftool -y -t error branch
+'
+
+test_expect_success PERL 'difftool forwards exit code with --trust-exit-code' '
+       test_config difftool.error.cmd false &&
+       test_must_fail git difftool -y --trust-exit-code -t error branch
+'
+
+test_expect_success PERL 'difftool honors difftool.trustExitCode = true' '
+       test_config difftool.error.cmd false &&
+       test_config difftool.trustExitCode true &&
+       test_must_fail git difftool -y -t error branch
+'
+
+test_expect_success PERL 'difftool honors difftool.trustExitCode = false' '
+       test_config difftool.error.cmd false &&
+       test_config difftool.trustExitCode false &&
+       git difftool -y -t error branch
+'
+
+test_expect_success PERL 'difftool ignores exit code with --no-trust-exit-code' '
+       test_config difftool.error.cmd false &&
+       test_config difftool.trustExitCode true &&
+       git difftool -y --no-trust-exit-code -t error branch
+'
+
+test_expect_success PERL 'difftool stops on error with --trust-exit-code' '
+       test_when_finished "rm -f for-diff .git/fail-right-file" &&
+       test_when_finished "git reset -- for-diff" &&
+       write_script .git/fail-right-file <<-\EOF &&
+       echo "$2"
+       exit 1
+       EOF
+       >for-diff &&
+       git add for-diff &&
+       echo file >expect &&
+       test_must_fail git difftool -y --trust-exit-code \
+               --extcmd .git/fail-right-file branch >actual &&
+       test_cmp expect actual
+'
+
 test_expect_success PERL 'difftool honors --gui' '
        difftool_test_setup &&
        test_config merge.tool bogus-tool &&