This question is based on VonC's comment at the thread.
Is Git's auto-detection for difftool or mergetool scripted or is it within some Git executable?
This question is based on VonC's comment at the thread.
Is Git's auto-detection for difftool or mergetool scripted or is it within some Git executable?
It's scripted in git-mergetool. I found this at line 344 of my copy.
if test -z "$merge_tool"; then
merge_tool=`git config merge.tool`
if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
echo >&2 "Resetting to default..."
unset merge_tool
fi
fi
if test -z "$merge_tool" ; then
if test -n "$DISPLAY"; then
merge_tool_candidates="kdiff3 tkdiff xxdiff meld gvimdiff"
if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
merge_tool_candidates="meld $merge_tool_candidates"
fi
if test "$KDE_FULL_SESSION" = "true"; then
merge_tool_candidates="kdiff3 $merge_tool_candidates"
fi
fi
if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
merge_tool_candidates="$merge_tool_candidates emerge"
fi
(snip)
As mentioned in the git mergetool man page,
--tool=<tool>
Use the merge resolution program specified by .
Valid merge tools are: kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge, diffuse, tortoisemerge, opendiff and araxis.
Now, where does that list comes from?
Actually, those tools (and their custom options) are used in the script:
<Git>/libexec/git-core/git-mergetool--lib
and used by the script git-mergetool, which does the selection based on git config merge.tool
command.
But there is a bit of 'auto-selection' based on the valid_tool() function in git-mergetool--lib:
valid_tool ()
It uses get_merge_tool_cmd() which is based on mergetool.<aMergeToolName>.cmd
.
If that setting remain in one of the git config files... that tool will be selected.
Right..., Jakub Narębski just pointed out the right section in the git-mergetool--lib
script:
get_merge_tool () {
# Check if a merge tool has been configured
merge_tool=$(get_configured_merge_tool)
# Try to guess an appropriate merge tool if no tool has been set.
if test -z "$merge_tool"; then
merge_tool="$(guess_merge_tool)" || exit
fi
echo "$merge_tool"
}
That function aptly named guess_merge_tool()
(you think I should be able to find it!...) does amongst other thing, the following, which could explain it detects opendiff:
# Loop over each candidate and stop when a valid merge tool is found.
for i in $tools
do
merge_tool_path="$(translate_merge_tool_path "$i")"
if type "$merge_tool_path" > /dev/null 2>&1; then
echo "$i"
return 0
fi
done