@@ -1,5 +1,14 @@
#!/bin/sh
+# NOTICE:
+# This testsuite does a number of diffs and checks that the output match.
+# However, it is a "garbage in, garbage out" situation; the trees have
+# duplicate entries for individual paths, and it results in diffs that do
+# not make much sense. As such, it is not clear that the diffs are
+# "correct". The primary purpose of these tests was to verify that
+# diff-tree does not segfault, but there is perhaps some value in ensuring
+# that the diff output isn't wildly unreasonable.
+
test_description='test tree diff when trees have duplicate entries'
. ./test-lib.sh
@@ -57,7 +66,16 @@ test_expect_success 'create trees with duplicate entries' '
git tag two $outer_two
'
-test_expect_success 'diff-tree between trees' '
+test_expect_success 'create tree without duplicate entries' '
+ blob_one=$(echo one | git hash-object -w --stdin) &&
+ outer_three=$(make_tree \
+ 100644 renamed $blob_one
+ ) &&
+ git tag three $outer_three
+'
+
+test_expect_success 'diff-tree between duplicate trees' '
+ # See NOTICE at top of file
{
printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
@@ -71,9 +89,34 @@ test_expect_success 'diff-tree between trees' '
'
test_expect_success 'diff-tree with renames' '
- # same expectation as above, since we disable rename detection
+ # See NOTICE at top of file.
git diff-tree -M -r --no-abbrev one two >actual &&
test_cmp expect actual
'
+test_expect_success 'diff-tree FROM duplicate tree' '
+ # See NOTICE at top of file.
+ {
+ printf ":100644 000000 $blob_one $ZERO_OID D\touter/inner\n" &&
+ printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+ printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+ printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+ printf ":000000 100644 $ZERO_OID $blob_one A\trenamed\n"
+ } >expect &&
+ git diff-tree -r --no-abbrev one three >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'diff-tree FROM duplicate tree, with renames' '
+ # See NOTICE at top of file.
+ {
+ printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+ printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+ printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
+ printf ":100644 100644 $blob_one $blob_one R100\touter/inner\trenamed\n"
+ } >expect &&
+ git diff-tree -M -r --no-abbrev one three >actual &&
+ test_cmp expect actual
+'
+
test_done