git/t/t4107-apply-ignore-whitespace.sh
Patrick Steinhardt 3fc4eab466 apply: refactor struct image to use a struct strbuf
The `struct image` uses a character array to track the pre- or postimage
of a patch operation. This has multiple downsides:

  - It is somewhat hard to track memory ownership. In fact, we have
    several memory leaks in git-apply(1) because we do not (and cannot
    easily) free the buffer in all situations.

  - We have to reinvent the wheel and manually implement a lot of
    functionality that would already be provided by `struct strbuf`.

  - We have to carefully track whether `update_pre_post_images()` can do
    an in-place update of the postimage or whether it has to allocate a
    new buffer for it.

This is all rather cumbersome, and especially `update_pre_post_images()`
is really hard to understand as a consequence even though what it is
doing is rather trivial.

Refactor the code to use a `struct strbuf` instead, addressing all of
the above. Like this we can easily perform in-place updates in all
situations, the logic to perform those updates becomes way simpler and
the lifetime of the buffer becomes a ton easier to track.

This refactoring also plugs some leaking buffers as a side effect.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-17 13:53:30 -07:00

196 lines
4.0 KiB
Bash
Executable File

#!/bin/sh
#
# Copyright (c) 2009 Giuseppe Bilotta
#
test_description='git-apply --ignore-whitespace.'
TEST_PASSES_SANITIZE_LEAK=true
. ./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);
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_cmp main.c.final main.c
'
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 fails (leading whitespace differences matter)' '
test_must_fail git apply patch5.patch
'
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_expect_success 'apply --ignore-space-change --inaccurate-eof' '
echo 1 >file &&
git apply --ignore-space-change --inaccurate-eof <<-\EOF &&
diff --git a/file b/file
--- a/file
+++ b/file
@@ -1 +1 @@
-1
+2
EOF
printf 2 >expect &&
test_cmp expect file
'
test_done