1 files changed, 121 insertions, 0 deletions
diff --git a/t/t4042-diff-textconv-caching.sh b/t/t4042-diff-textconv-caching.sh
new file mode 100755
index 000000000000..bf33aedf4b22
--- /dev/null
+++ b/t/t4042-diff-textconv-caching.sh
@@ -0,0 +1,121 @@
+#!/bin/sh
+
+test_description='test textconv caching'
+. ./test-lib.sh
+
+cat >helper <<'EOF'
+#!/bin/sh
+sed 's/^/converted: /' "$@" >helper.out
+cat helper.out
+EOF
+chmod +x helper
+
+test_expect_success 'setup' '
+	echo foo content 1 >foo.bin &&
+	echo bar content 1 >bar.bin &&
+	git add . &&
+	git commit -m one &&
+	foo1=$(git rev-parse --short HEAD:foo.bin) &&
+	bar1=$(git rev-parse --short HEAD:bar.bin) &&
+	echo foo content 2 >foo.bin &&
+	echo bar content 2 >bar.bin &&
+	git commit -a -m two &&
+	foo2=$(git rev-parse --short HEAD:foo.bin) &&
+	bar2=$(git rev-parse --short HEAD:bar.bin) &&
+	echo "*.bin diff=magic" >.gitattributes &&
+	git config diff.magic.textconv ./helper &&
+	git config diff.magic.cachetextconv true
+'
+
+cat >expect <<EOF
+diff --git a/bar.bin b/bar.bin
+index $bar1..$bar2 100644
+--- a/bar.bin
++++ b/bar.bin
+@@ -1 +1 @@
+-converted: bar content 1
++converted: bar content 2
+diff --git a/foo.bin b/foo.bin
+index $foo1..$foo2 100644
+--- a/foo.bin
++++ b/foo.bin
+@@ -1 +1 @@
+-converted: foo content 1
++converted: foo content 2
+EOF
+
+test_expect_success 'first textconv works' '
+	git diff HEAD^ HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'cached textconv produces same output' '
+	git diff HEAD^ HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'cached textconv does not run helper' '
+	rm -f helper.out &&
+	git diff HEAD^ HEAD >actual &&
+	test_cmp expect actual &&
+	! test -r helper.out
+'
+
+cat >expect <<EOF
+diff --git a/bar.bin b/bar.bin
+index $bar1..$bar2 100644
+--- a/bar.bin
++++ b/bar.bin
+@@ -1,2 +1,2 @@
+ converted: other
+-converted: bar content 1
++converted: bar content 2
+diff --git a/foo.bin b/foo.bin
+index $foo1..$foo2 100644
+--- a/foo.bin
++++ b/foo.bin
+@@ -1,2 +1,2 @@
+ converted: other
+-converted: foo content 1
++converted: foo content 2
+EOF
+test_expect_success 'changing textconv invalidates cache' '
+	echo other >other &&
+	git config diff.magic.textconv "./helper other" &&
+	git diff HEAD^ HEAD >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<EOF
+diff --git a/bar.bin b/bar.bin
+index $bar1..$bar2 100644
+--- a/bar.bin
++++ b/bar.bin
+@@ -1,2 +1,2 @@
+ converted: other
+-converted: bar content 1
++converted: bar content 2
+diff --git a/foo.bin b/foo.bin
+index $foo1..$foo2 100644
+--- a/foo.bin
++++ b/foo.bin
+@@ -1 +1 @@
+-converted: foo content 1
++converted: foo content 2
+EOF
+test_expect_success 'switching diff driver produces correct results' '
+	git config diff.moremagic.textconv ./helper &&
+	echo foo.bin diff=moremagic >>.gitattributes &&
+	git diff HEAD^ HEAD >actual &&
+	test_cmp expect actual
+'
+
+# The point here is to test that we can log the notes cache and still use it to
+# produce a diff later (older versions of git would segfault on this). It's
+# much more likely to come up in the real world with "log --all -p", but using
+# --no-walk lets us reliably reproduce the order of traversal.
+test_expect_success 'log notes cache and still use cache for -p' '
+	git log --no-walk -p refs/notes/textconv/magic HEAD
+'
+
+test_done