Merge branch 'sg/bash-prompt-dirty-orphan' into maint

Produce correct "dirty" marker for shell prompts, even when we
are on an orphan or an unborn branch.

* sg/bash-prompt-dirty-orphan:
  bash prompt: indicate dirty index even on orphan branches
  bash prompt: remove a redundant 'git diff' option
  bash prompt: test dirty index and worktree while on an orphan branch

Author: gitster

contrib/completion/git-prompt.sh

@@ -476,10 +476,9 @@ __git_ps1 ()
 		if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ] &&
 		   [ "$(git config --bool bash.showDirtyState)" != "false" ]
 		then
-			git diff --no-ext-diff --quiet --exit-code || w="*"
-			if [ -n "$short_sha" ]; then
-				git diff-index --cached --quiet HEAD -- || i="+"
-			else
+			git diff --no-ext-diff --quiet || w="*"
+			git diff --no-ext-diff --cached --quiet || i="+"
+			if [ -z "$short_sha" ] && [ -z "$i" ]; then
 				i="#"
 			fi
 		fi

t/t9903-bash-prompt.sh

@@ -273,11 +273,36 @@ test_expect_success 'prompt - dirty status indicator - dirty index and worktree'
 	test_cmp expected "$actual"
 '
 
-test_expect_success 'prompt - dirty status indicator - before root commit' '
-	printf " (master #)" >expected &&
+test_expect_success 'prompt - dirty status indicator - orphan branch - clean' '
+	printf " (orphan #)" >expected &&
+	test_when_finished "git checkout master" &&
+	git checkout --orphan orphan &&
+	git reset --hard &&
+	(
+		GIT_PS1_SHOWDIRTYSTATE=y &&
+		__git_ps1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'prompt - dirty status indicator - orphan branch - dirty index' '
+	printf " (orphan +)" >expected &&
+	test_when_finished "git checkout master" &&
+	git checkout --orphan orphan &&
+	(
+		GIT_PS1_SHOWDIRTYSTATE=y &&
+		__git_ps1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'prompt - dirty status indicator - orphan branch - dirty index and worktree' '
+	printf " (orphan *+)" >expected &&
+	test_when_finished "git checkout master" &&
+	git checkout --orphan orphan &&
+	>file &&
 	(
 		GIT_PS1_SHOWDIRTYSTATE=y &&
-		cd otherrepo &&
 		__git_ps1 >"$actual"
 	) &&
 	test_cmp expected "$actual"