mergetools/meld: make usage of `--output` configurable and more robust

Older versions of meld listed --output in `meld --help`.
Newer versions only mention `meld [OPTIONS...]`.
Improve the checks to catch these newer versions.

Add a `mergetool.meld.hasOutput` configuration to allow
overriding the heuristic.

Reported-by: Andrey Novoseltsev <novoselt@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config.txt b/Documentation/config.txt
index c55c22ab7be94e798164a48622aca21dd4daa44f..382e12c69efc520978390fc97483ac388b7e4a94 100644 (file)
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1754,6 +1754,15 @@ mergetool.<tool>.trustExitCode::
        if the file has been updated, otherwise the user is prompted to
        indicate the success of the merge.
 
        if the file has been updated, otherwise the user is prompted to
        indicate the success of the merge.
 

+mergetool.meld.hasOutput::
+       Older versions of `meld` do not support the `--output` option.
+       Git will attempt to detect whether `meld` supports `--output`
+       by inspecting the output of `meld --help`.  Configuring
+       `mergetool.meld.hasOutput` will make Git skip these checks and
+       use the configured value instead.  Setting `mergetool.meld.hasOutput`
+       to `true` tells Git to unconditionally use the `--output` option,
+       and `false` avoids using `--output`.
+

 mergetool.keepBackup::
        After performing a merge, the original file with conflict markers
        can be saved as a file with a `.orig` extension.  If this variable
 mergetool.keepBackup::
        After performing a merge, the original file with conflict markers
        can be saved as a file with a `.orig` extension.  If this variable

diff --git a/mergetools/meld b/mergetools/meld
index cb672a55192cb44335aa2cbe1f10004bb26d86ff..83ebdfb4c328ac79af38bfe935f0dbfa7fb6f53b 100644 (file)
--- a/mergetools/meld
+++ b/mergetools/meld
@@ -18,13 +18,18 @@ merge_cmd () {
        check_unchanged
 }
 
        check_unchanged
 }
 

-# Check whether 'meld --output <file>' is supported
+# Check whether we should use 'meld --output <file>'

 check_meld_for_output_version () {
        meld_path="$(git config mergetool.meld.path)"
        meld_path="${meld_path:-meld}"
 
 check_meld_for_output_version () {
        meld_path="$(git config mergetool.meld.path)"
        meld_path="${meld_path:-meld}"
 

-       if "$meld_path" --help 2>&1 | grep -e --output >/dev/null
+       if meld_has_output_option=$(git config --bool mergetool.meld.hasOutput)

        then
        then

+               : use configured value
+       elif "$meld_path" --help 2>&1 |
+               grep -e '--output=' -e '\[OPTION\.\.\.\]' >/dev/null
+       then
+               : old ones mention --output and new ones just say OPTION...

                meld_has_output_option=true
        else
                meld_has_output_option=false
                meld_has_output_option=true
        else
                meld_has_output_option=false