Merge branch 'sp/complete-ext-alias'

* sp/complete-ext-alias:
  completion: handle '!f() { ... }; f' and "!sh -c '...' -" aliases

contrib/completion/git-completion.bash

@@ -21,6 +21,12 @@
 #        source ~/.git-completion.sh
 #    3) Consider changing your PS1 to also show the current branch,
 #       see git-prompt.sh for details.
+#
+# If you use complex aliases of form '!f() { ... }; f', you can use the null
+# command ':' as the first command in the function body to declare the desired
+# completion style.  For example '!f() { : git commit ; ... }; f' will
+# tell the completion to use commit completion.  This also works with aliases
+# of form "!sh -c '...'".  For example, "!sh -c ': git commit ; ... '".
 
 case "$COMP_WORDBREAKS" in
 *:*) : great ;;
@@ -781,6 +787,10 @@ __git_aliased_command ()
 		-*)	: option ;;
 		*=*)	: setting env ;;
 		git)	: git itself ;;
+		\(\))   : skip parens of shell function definition ;;
+		{)	: skip start of shell helper function ;;
+		:)	: skip null command ;;
+		\'*)	: skip opening quote after sh -c ;;
 		*)
 			echo "$word"
 			return

t/t9902-completion.sh

@@ -550,6 +550,33 @@ test_expect_success 'complete files' '
 	test_completion "git add mom" "momified"
 '
 
+test_expect_success "completion uses <cmd> completion for alias: !sh -c 'git <cmd> ...'" '
+	test_config alias.co "!sh -c '"'"'git checkout ...'"'"'" &&
+	test_completion "git co m" <<-\EOF
+	master Z
+	mybranch Z
+	mytag Z
+	EOF
+'
+
+test_expect_success 'completion uses <cmd> completion for alias: !f () { VAR=val git <cmd> ... }' '
+	test_config alias.co "!f () { VAR=val git checkout ... ; } f" &&
+	test_completion "git co m" <<-\EOF
+	master Z
+	mybranch Z
+	mytag Z
+	EOF
+'
+
+test_expect_success 'completion used <cmd> completion for alias: !f() { : git <cmd> ; ... }' '
+	test_config alias.co "!f() { : git checkout ; if ... } f" &&
+	test_completion "git co m" <<-\EOF
+	master Z
+	mybranch Z
+	mytag Z
+	EOF
+'
+
 test_expect_failure 'complete with tilde expansion' '
 	git init tmp && cd tmp &&
 	test_when_finished "cd .. && rm -rf tmp" &&