1 files changed, 100 insertions, 0 deletions
diff --git a/t/t5536-fetch-conflicts.sh b/t/t5536-fetch-conflicts.sh
new file mode 100755
index 0000000000..6c5d3a4ce0
--- /dev/null
+++ b/t/t5536-fetch-conflicts.sh
@@ -0,0 +1,100 @@
+#!/bin/sh
+
+test_description='fetch handles conflicting refspecs correctly'
+
+. ./test-lib.sh
+
+D=$(pwd)
+
+setup_repository () {
+	git init "$1" && (
+		cd "$1" &&
+		git config remote.origin.url "$D" &&
+		shift &&
+		for refspec in "$@"
+		do
+			git config --add remote.origin.fetch "$refspec"
+		done
+	)
+}
+
+verify_stderr () {
+	cat >expected &&
+	# We're not interested in the error
+	# "fatal: The remote end hung up unexpectedly":
+	grep -E '^(fatal|warning):' <error | grep -v 'hung up' >actual | sort &&
+	test_cmp expected actual
+}
+
+test_expect_success 'setup' '
+	git commit --allow-empty -m "Initial" &&
+	git branch branch1 &&
+	git tag tag1 &&
+	git commit --allow-empty -m "First" &&
+	git branch branch2 &&
+	git tag tag2
+'
+
+test_expect_success 'fetch with no conflict' '
+	setup_repository ok "+refs/heads/*:refs/remotes/origin/*" && (
+		cd ok &&
+		git fetch origin
+	)
+'
+
+test_expect_success 'fetch conflict: config vs. config' '
+	setup_repository ccc \
+		"+refs/heads/branch1:refs/remotes/origin/branch1" \
+		"+refs/heads/branch2:refs/remotes/origin/branch1" && (
+		cd ccc &&
+		test_must_fail git fetch origin 2>error &&
+		verify_stderr <<-\EOF
+		fatal: Cannot fetch both refs/heads/branch1 and refs/heads/branch2 to refs/remotes/origin/branch1
+		EOF
+	)
+'
+
+test_expect_success 'fetch duplicate: config vs. config' '
+	setup_repository dcc \
+		"+refs/heads/*:refs/remotes/origin/*" \
+		"+refs/heads/branch1:refs/remotes/origin/branch1" && (
+		cd dcc &&
+		git fetch origin
+	)
+'
+
+test_expect_success 'fetch conflict: arg overrides config' '
+	setup_repository aoc \
+		"+refs/heads/*:refs/remotes/origin/*" && (
+		cd aoc &&
+		git fetch origin refs/heads/branch2:refs/remotes/origin/branch1
+	)
+'
+
+test_expect_success 'fetch conflict: arg vs. arg' '
+	setup_repository caa && (
+		cd caa &&
+		test_must_fail git fetch origin \
+			refs/heads/*:refs/remotes/origin/* \
+			refs/heads/branch2:refs/remotes/origin/branch1 2>error &&
+		verify_stderr <<-\EOF
+		fatal: Cannot fetch both refs/heads/branch1 and refs/heads/branch2 to refs/remotes/origin/branch1
+		EOF
+	)
+'
+
+test_expect_success 'fetch conflict: criss-cross args' '
+	setup_repository xaa \
+		"+refs/heads/*:refs/remotes/origin/*" && (
+		cd xaa &&
+		git fetch origin \
+			refs/heads/branch1:refs/remotes/origin/branch2 \
+			refs/heads/branch2:refs/remotes/origin/branch1 2>error &&
+		verify_stderr <<-\EOF
+		warning: refs/remotes/origin/branch1 usually tracks refs/heads/branch1, not refs/heads/branch2
+		warning: refs/remotes/origin/branch2 usually tracks refs/heads/branch2, not refs/heads/branch1
+		EOF
+	)
+'
+
+test_done