combine-diff: coalesce lost lines optimally

diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index c8e41c1d42b5a5be84fad5508c71d33885962a51..9320b4f94c25bf376a004c2c0d4451c0fd96f969 100755 (executable)
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -484,4 +484,19 @@ test_expect_success 'avoid uninteresting refs' '
        test_cmp expected actual
 '
 
+cat > expected << EOF
+reset refs/heads/master
+from :14
+
+EOF
+
+test_expect_success 'refs are updated even if no commits need to be exported' '
+       > tmp-marks &&
+       git fast-export --import-marks=tmp-marks \
+               --export-marks=tmp-marks master > /dev/null &&
+       git fast-export --import-marks=tmp-marks \
+               --export-marks=tmp-marks master > actual &&
+       test_cmp expected actual
+'
+
 test_done