[PATCH 1/4] difftool--helper: Update copyright and remove distracting comments

[PATCH 1/4] difftool--helper: Update copyright and remove distracting comments

[David Aguilar]

Some of the comments in git-difftool--helper are not needed because
the code is sufficiently readable without them.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-difftool--helper.sh |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index 57e8e32..1b13808 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -3,9 +3,8 @@
 # This script is typically launched by using the 'git difftool'
 # convenience command.
 #
-# Copyright (c) 2009 David Aguilar
+# Copyright (c) 2009-2010 David Aguilar
 
-# Load common functions from git-mergetool--lib
 TOOL_MODE=diff
 . git-mergetool--lib
 
@@ -20,7 +19,6 @@ should_prompt () {
 	fi
 }
 
-# Sets up shell variables and runs a merge tool
 launch_merge_tool () {
 	# Merged is the filename as it appears in the work tree
 	# Local is the contents of a/filename
@@ -39,7 +37,6 @@ launch_merge_tool () {
 		read ans
 	fi
 
-	# Run the appropriate merge tool command
 	run_merge_tool "$merge_tool"
 }
 
-- 
1.6.6.4.g20a38b.dirty

[PATCH 2/4] difftool--helper: Remove use of the GIT_MERGE_TOOL variable

[David Aguilar]

An undocumented mis-feature in git-difftool is that it allows you
to specify a default difftool by setting GIT_MERGE_TOOL.
This behavior was never documented and was included as an
oversight back when git-difftool was maintained outside of git.

git-mergetool never honored GIT_MERGE_TOOL so neither should
git-difftool.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-difftool--helper.sh |    9 ++++-----
 t/t7800-difftool.sh     |    9 ---------
 2 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index 1b13808..3621f28 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -40,11 +40,10 @@ launch_merge_tool () {
 	run_merge_tool "$merge_tool"
 }
 
-# Allow GIT_DIFF_TOOL and GIT_MERGE_TOOL to provide default values
-test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
-test -n "$GIT_DIFF_TOOL" && merge_tool="$GIT_DIFF_TOOL"
-
-if test -z "$merge_tool"; then
+# GIT_DIFF_TOOL indicates that --tool=... was specified
+if test -n "$GIT_DIFF_TOOL"; then
+	merge_tool="$GIT_DIFF_TOOL"
+else
 	merge_tool="$(get_merge_tool)" || exit
 fi
 
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 9bf6c98..eca51a8 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -32,7 +32,6 @@ restore_test_defaults()
 	# Restores the test defaults used by several tests
 	remove_config_vars
 	unset GIT_DIFF_TOOL
-	unset GIT_MERGE_TOOL
 	unset GIT_DIFFTOOL_PROMPT
 	unset GIT_DIFFTOOL_NO_PROMPT
 	git config diff.tool test-tool &&
@@ -107,15 +106,7 @@ test_expect_success 'GIT_DIFF_TOOL overrides' '
 	git config diff.tool bogus-tool &&
 	git config merge.tool bogus-tool &&
 
-	GIT_MERGE_TOOL=test-tool &&
-	export GIT_MERGE_TOOL &&
-	diff=$(git difftool --no-prompt branch) &&
-	test "$diff" = "branch" &&
-	unset GIT_MERGE_TOOL &&
-
-	GIT_MERGE_TOOL=bogus-tool &&
 	GIT_DIFF_TOOL=test-tool &&
-	export GIT_MERGE_TOOL &&
 	export GIT_DIFF_TOOL &&
 
 	diff=$(git difftool --no-prompt branch) &&
-- 
1.6.6.4.g20a38b.dirty

[PATCH 3/4] difftool: Allow specifying unconfigured commands with --extcmd

[David Aguilar]

git-difftool requires difftool.<tool>.cmd configuration even when
tools use the standard "$diffcmd $from $to" form.  This teaches
git-difftool to run these tools in lieu of configuration by
allowing the command to be specified on the command line.

Reference: http://article.gmane.org/gmane.comp.version-control.git/133377
Signed-off-by: David Aguilar <davvid@gmail.com>
---
 Documentation/git-difftool.txt |    5 +++++
 git-difftool--helper.sh        |   30 +++++++++++++++++++++++-------
 git-difftool.perl              |    4 ++++
 t/t7800-difftool.sh            |   19 ++++++++++++++++++-
 4 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index a5bce62..f67d2db 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -58,6 +58,11 @@ is set to the name of the temporary file containing the contents
 of the diff post-image.  `$BASE` is provided for compatibility
 with custom merge tool commands and has the same value as `$LOCAL`.
 
+--extcmd=<command>::
+	Specify a custom command for viewing diffs.
+	'git-difftool' ignores the configured defaults and runs
+	`$command $LOCAL $REMOTE` when this option is specified.
+
 -g::
 --gui::
 	When 'git-difftool' is invoked with the `-g` or `--gui` option
diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index 3621f28..d806eae 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -19,6 +19,11 @@ should_prompt () {
 	fi
 }
 
+# Indicates that --extcmd=... was specified
+use_ext_cmd () {
+	test -n "$GIT_DIFFTOOL_EXTCMD"
+}
+
 launch_merge_tool () {
 	# Merged is the filename as it appears in the work tree
 	# Local is the contents of a/filename
@@ -33,18 +38,29 @@ launch_merge_tool () {
 	# the user with the real $MERGED name before launching $merge_tool.
 	if should_prompt; then
 		printf "\nViewing: '$MERGED'\n"
-		printf "Hit return to launch '%s': " "$merge_tool"
+		if use_ext_cmd; then
+			printf "Hit return to launch '%s': " \
+				"$GIT_DIFFTOOL_EXTCMD"
+		else
+			printf "Hit return to launch '%s': " "$merge_tool"
+		fi
 		read ans
 	fi
 
-	run_merge_tool "$merge_tool"
+	if use_ext_cmd; then
+		$GIT_DIFFTOOL_EXTCMD "$LOCAL" "$REMOTE"
+	else
+		run_merge_tool "$merge_tool"
+	fi
+
 }
 
-# GIT_DIFF_TOOL indicates that --tool=... was specified
-if test -n "$GIT_DIFF_TOOL"; then
-	merge_tool="$GIT_DIFF_TOOL"
-else
-	merge_tool="$(get_merge_tool)" || exit
+if ! use_ext_cmd; then
+	if test -n "$GIT_DIFF_TOOL"; then
+		merge_tool="$GIT_DIFF_TOOL"
+	else
+		merge_tool="$(get_merge_tool)" || exit
+	fi
 fi
 
 # Launch the merge tool on each path provided by 'git diff'
diff --git a/git-difftool.perl b/git-difftool.perl
index 8c836e4..f8ff245 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -62,6 +62,10 @@ sub generate_command
 			$skip_next = 1;
 			next;
 		}
+		if ($arg =~ /^--extcmd=/) {
+			$ENV{GIT_DIFFTOOL_EXTCMD} = substr($arg, 9);
+			next;
+		}
 		if ($arg =~ /^--tool=/) {
 			$ENV{GIT_DIFF_TOOL} = substr($arg, 7);
 			next;
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index eca51a8..8ee186a 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -214,7 +214,24 @@ test_expect_success 'difftool.<tool>.path' '
 	diff=$(git difftool --tool=tkdiff --no-prompt branch) &&
 	git config --unset difftool.tkdiff.path &&
 	lines=$(echo "$diff" | grep file | wc -l) &&
-	test "$lines" -eq 1
+	test "$lines" -eq 1 &&
+
+	restore_test_defaults
+'
+
+test_expect_success 'difftool --extcmd=...' '
+	diff=$(git difftool --no-prompt --extcmd=cat branch) &&
+
+	lines=$(echo "$diff" | wc -l) &&
+	test "$lines" -eq 2 &&
+
+	lines=$(echo "$diff" | grep master | wc -l) &&
+	test "$lines" -eq 1 &&
+
+	lines=$(echo "$diff" | grep branch | wc -l) &&
+	test "$lines" -eq 1 &&
+
+	restore_test_defaults
 '
 
 test_done
-- 
1.6.6.4.g20a38b.dirty

[PATCH 4/4] git-diff.txt: Link to git-difftool

[David Aguilar]

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 Documentation/git-diff.txt |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/Documentation/git-diff.txt b/Documentation/git-diff.txt
index 0ac7112..723a648 100644
--- a/Documentation/git-diff.txt
+++ b/Documentation/git-diff.txt
@@ -157,6 +157,10 @@ $ git diff -R                          <2>
 rewrites (very expensive).
 <2> Output diff in reverse.
 
+SEE ALSO
+--------
+linkgit:git-difftool[1]::
+	Show changes using common diff tools
 
 Author
 ------
-- 
1.6.6.4.g20a38b.dirty