From 29dc13319883f97618de6f03e8ffc5dc810d8786 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 17 Mar 2008 16:47:18 -0700
Subject: [PATCH] git-merge-one-file: fix longstanding stupid thinko

When a merge result creates a new file, and when our side already has a
file in the path, taking the merge result may clobber the untracked file.
However, the logic to detect this situation was totally the wrong way.  We
should complain when the file exists, not when the file does not exist.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-merge-one-file.sh       |  5 ++--
 t/t1004-read-tree-m-u-wf.sh | 46 +++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/git-merge-one-file.sh b/git-merge-one-file.sh
index 9ee3f8045..e1eb96326 100755
--- a/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@ -48,10 +48,11 @@ case "${1:-.}${2:-.}${3:-.}" in
 	;;
 "..$3")
 	echo "Adding $4"
-	test -f "$4" || {
+	if test -f "$4"
+	then
 		echo "ERROR: untracked $4 is overwritten by the merge."
 		exit 1
-	}
+	fi
 	git update-index --add --cacheinfo "$7" "$3" "$4" &&
 		exec git checkout-index -u -f -- "$4"
 	;;
diff --git a/t/t1004-read-tree-m-u-wf.sh b/t/t1004-read-tree-m-u-wf.sh
index 9d1371c2c..283e77cc5 100755
--- a/t/t1004-read-tree-m-u-wf.sh
+++ b/t/t1004-read-tree-m-u-wf.sh
@@ -157,4 +157,50 @@ test_expect_success '3-way not overwriting local changes (their side)' '
 
 '
 
+test_expect_success 'D/F setup' '
+
+	git reset --hard &&
+
+	git checkout side-a &&
+	rm -f subdir/file2 &&
+	mkdir subdir/file2 &&
+	echo qfwfq >subdir/file2/another &&
+	git add subdir/file2/another &&
+	test_tick &&
+	git commit -m "side-a changes file2 to directory"
+
+'
+
+test_expect_success 'D/F' '
+
+	git checkout side-b &&
+	git read-tree -m -u branch-point side-b side-a &&
+	git ls-files -u >actual &&
+	(
+		a=$(git rev-parse branch-point:subdir/file2)
+		b=$(git rev-parse side-a:subdir/file2/another)
+		echo "100644 $a 1	subdir/file2"
+		echo "100644 $a 2	subdir/file2"
+		echo "100644 $b 3	subdir/file2/another"
+	) >expect &&
+	test_cmp actual expect
+
+'
+
+test_expect_success 'D/F resolve' '
+
+	git reset --hard &&
+	git checkout side-b &&
+	git merge-resolve branch-point -- side-b side-a
+
+'
+
+test_expect_success 'D/F recursive' '
+
+	git reset --hard &&
+	git checkout side-b &&
+	git merge-recursive branch-point -- side-b side-a
+
+'
+
 test_done
-- 
2.30.2