git apply: option to ignore whitespace differences

Introduce --ignore-whitespace option and corresponding config bool to
ignore whitespace differences while applying patches, akin to the
'patch' program.

'git am', 'git rebase' and the bash git completion are made aware of
this option.

Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 185 insertions, 0 deletions

diff --git a/t/t4107-apply-ignore-whitespace.sh b/t/t4107-apply-ignore-whitespace.sh
new file mode 100755
index 0000000000..484654d6e4
--- /dev/null
+++ b/t/t4107-apply-ignore-whitespace.sh
@@ -0,0 +1,185 @@
+#!/bin/sh
+#
+# Copyright (c) 2009 Giuseppe Bilotta
+#
+
+test_description='git-apply --ignore-whitespace.
+
+'
+. ./test-lib.sh
+
+# This primes main.c file that indents without using HT at all.
+# Various patches with HT and other spaces are attempted in the test.
+
+cat > patch1.patch <<\EOF
+diff --git a/main.c b/main.c
+new file mode 100644
+--- /dev/null
++++ b/main.c
+@@ -0,0 +1,22 @@
++#include <stdio.h>
++
++void print_int(int num);
++int func(int num);
++
++int main() {
++       int i;
++
++       for (i = 0; i < 10; i++) {
++               print_int(func(i)); /* stuff */
++       }
++
++       return 0;
++}
++
++int func(int num) {
++       return num * num;
++}
++
++void print_int(int num) {
++       printf("%d", num);
++}
+EOF
+
+# Since whitespace is very significant and we want to prevent whitespace
+# mangling when creating this test from a patch, we protect 'fixable'
+# whitespace by replacing spaces with Z and replacing them at patch
+# creation time, hence the sed trick.
+
+# This patch will fail unless whitespace differences are being ignored
+
+sed -e 's/Z/ /g' > patch2.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -10,6 +10,8 @@
+Z		print_int(func(i)); /* stuff */
+Z	}
+Z
++	printf("\n");
++
+Z	return 0;
+Z}
+Z
+EOF
+
+# This patch will fail even if whitespace differences are being ignored,
+# because of the missing string at EOL. TODO: this testcase should be
+# improved by creating a line that has the same hash with and without
+# the final string.
+
+sed -e 's/Z/ /g' > patch3.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -10,3 +10,4 @@
+Z	for (i = 0; i < 10; i++) {
+Z		print_int(func(i));Z
++		/* stuff */
+Z	}
+EOF
+
+# This patch will fail even if whitespace differences are being ignored,
+# because of the missing EOL at EOF.
+
+sed -e 's/Z/ /g' > patch4.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -21,1 +21,1 @@
+-	};Z
+\ No newline at end of file
++	};
+EOF
+
+# This patch will fail unless whitespace differences are being ignored.
+
+sed -e 's/Z/ /g' > patch5.patch <<\EOF
+diff --git a/main.c b/main.c
+--- a/main.c
++++ b/main.c
+@@ -2,2 +2,3 @@
+Z	void print_int(int num);
++	/* a comment */
+Z	int func(int num);
+EOF
+
+# And this is how the final output should be.  Patches introduce
+# HTs but the original SP indents are mostly kept.
+
+sed -e 's/T/	/g' > main.c.final <<\EOF
+#include <stdio.h>
+
+void print_int(int num);
+T/* a comment */
+int func(int num);
+
+int main() {
+       int i;
+
+       for (i = 0; i < 10; i++) {
+               print_int(func(i)); /* stuff */
+       }
+
+Tprintf("\n");
+
+       return 0;
+}
+
+int func(int num) {
+       return num * num;
+}
+
+void print_int(int num) {
+       printf("%d", num);
+}
+EOF
+
+test_expect_success 'file creation' '
+	git-apply patch1.patch
+'
+
+test_expect_success 'patch2 fails (retab)' '
+	test_must_fail git-apply patch2.patch
+'
+
+test_expect_success 'patch2 applies with --ignore-whitespace' '
+	git-apply --ignore-whitespace patch2.patch
+'
+
+test_expect_success 'patch2 reverse applies with --ignore-space-change' '
+	git-apply -R --ignore-space-change patch2.patch
+'
+
+git config apply.ignorewhitespace change
+
+test_expect_success 'patch2 applies (apply.ignorewhitespace = change)' '
+	git-apply patch2.patch
+'
+
+test_expect_success 'patch3 fails (missing string at EOL)' '
+	test_must_fail git-apply patch3.patch
+'
+
+test_expect_success 'patch4 fails (missing EOL at EOF)' '
+	test_must_fail git-apply patch4.patch
+'
+
+test_expect_success 'patch5 applies (leading whitespace)' '
+	git-apply patch5.patch
+'
+
+test_expect_success 'patches do not mangle whitespace' '
+	test_cmp main.c main.c.final
+'
+
+test_expect_success 're-create file (with --ignore-whitespace)' '
+	rm -f main.c &&
+	git-apply patch1.patch
+'
+
+test_expect_success 'patch5 fails (--no-ignore-whitespace)' '
+	test_must_fail git-apply --no-ignore-whitespace patch5.patch
+'
+
+test_done