tests: do not rely on external "patch"

Some of our tests assumed a working "patch" command to produce expected
results when checking "git-apply", but some systems have broken "patch".

We can compare our output with expected output that is precomputed
instead to sidestep this issue.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 78 insertions, 0 deletions

diff --git a/t/t4109/expect-1 b/t/t4109/expect-1
new file mode 100644
index 0000000000..1db5ff1050
--- /dev/null
+++ b/t/t4109/expect-1
@@ -0,0 +1,31 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+int func(int num);
+void print_int(int num);
+void print_ln();
+
+int main() {
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		print_int(func(i));
+	}
+
+	print_ln();
+
+	return 0;
+}
+
+int func(int num) {
+	return num * num;
+}
+
+void print_int(int num) {
+	printf("%d", num);
+}
+
+void print_ln() {
+	printf("\n");
+}
+
diff --git a/t/t4109/expect-2 b/t/t4109/expect-2
new file mode 100644
index 0000000000..bc52924112
--- /dev/null
+++ b/t/t4109/expect-2
@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+int func(int num);
+void print_int(int num);
+
+int main() {
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		print_int(func(i));
+	}
+
+	return 0;
+}
+
+int func(int num) {
+	return num * num;
+}
+
+void print_int(int num) {
+	printf("%d", num);
+}
+
diff --git a/t/t4109/expect-3 b/t/t4109/expect-3
new file mode 100644
index 0000000000..cd2a475feb
--- /dev/null
+++ b/t/t4109/expect-3
@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+int func(int num);
+int func2(int num);
+
+int main() {
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		printf("%d", func(i));
+		printf("%d", func3(i));
+	}
+
+	return 0;
+}
+
+int func(int num) {
+	return num * num;
+}
+
+int func2(int num) {
+	return num * num * num;
+}
+