From b6967c393aaa9bc8fcb1f248f94a4deb897248cb Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Thu, 6 Jun 2019 14:02:17 +0200
Subject: attr_file: refactor stripping of trailing spaces

The stripping of trailing spaces currently happens as part of
`git_attr_fnmatch__parse`. As we aren't currently parsing
trailing whitespaces correct in case they're escaped, we'll have
to change that code, though. To make actual behavioural change
easier to review, refactor the code up-front by pulling it out
into its own function that is expected to retain the exact same
functionality as before. Like this, the fix will be trivial to
apply.
---
 src/attr_file.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/attr_file.c b/src/attr_file.c
index aef3e64af..b2c60f204 100644
--- a/src/attr_file.c
+++ b/src/attr_file.c
@@ -559,6 +559,19 @@ void git_attr_path__free(git_attr_path *info)
  *   "cat-file.c" but not "mozilla-sha1/sha1.c".
  */
 
+/*
+ * Determine the length of trailing spaces.
+ */
+static size_t trailing_space_length(const char *p, size_t len)
+{
+	size_t n;
+	for (n = len; n; n--) {
+		if (p[n-1] != ' ' && p[n-1] != '\t')
+			break;
+	}
+	return len - n;
+}
+
 /*
  * This will return 0 if the spec was filled out,
  * GIT_ENOTFOUND if the fnmatch does not require matching, or
@@ -646,9 +659,10 @@ int git_attr_fnmatch__parse(
 			return GIT_ENOTFOUND;
 
 	/* Remove trailing spaces. */
-	while (pattern[spec->length - 1] == ' ' || pattern[spec->length - 1] == '\t')
-		if (--spec->length == 0)
-			return GIT_ENOTFOUND;
+	spec->length -= trailing_space_length(pattern, spec->length);
+
+	if (spec->length == 0)
+		return GIT_ENOTFOUND;
 
 	if (pattern[spec->length - 1] == '/') {
 		spec->length--;
-- 
cgit v1.2.1


From d81e7866aba52625aa3100764d77c73adba58c8e Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Thu, 6 Jun 2019 14:11:44 +0200
Subject: ignore: handle escaped trailing whitespace

The gitignore's pattern format specifies that "Trailing spaces
are ignored unless they are quoted with backslash ("\")". We do
not honor this currently and will treat a pattern "foo\ " as if
it was "foo\" only and a pattern "foo\ \ " as "foo\ \".

Fix our code to handle those special cases and add tests to avoid
regressions.
---
 src/attr_file.c     |  6 ++++--
 tests/attr/ignore.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/src/attr_file.c b/src/attr_file.c
index b2c60f204..40262eca6 100644
--- a/src/attr_file.c
+++ b/src/attr_file.c
@@ -560,13 +560,15 @@ void git_attr_path__free(git_attr_path *info)
  */
 
 /*
- * Determine the length of trailing spaces.
+ * Determine the length of trailing spaces. Escaped spaces do not count as
+ * trailing whitespace.
  */
 static size_t trailing_space_length(const char *p, size_t len)
 {
 	size_t n;
 	for (n = len; n; n--) {
-		if (p[n-1] != ' ' && p[n-1] != '\t')
+		if ((p[n-1] != ' ' && p[n-1] != '\t') ||
+		    (n > 1 && p[n-2] == '\\'))
 			break;
 	}
 	return len - n;
diff --git a/tests/attr/ignore.c b/tests/attr/ignore.c
index 1bf06fc1f..ea8a14192 100644
--- a/tests/attr/ignore.c
+++ b/tests/attr/ignore.c
@@ -61,6 +61,52 @@ void test_attr_ignore__ignore_space(void)
 	assert_is_ignored(true, "NewFolder/NewFolder/File.txt");
 }
 
+void test_attr_ignore__intermittent_space(void)
+{
+	cl_git_rewritefile("attr/.gitignore", "foo bar\n");
+
+	assert_is_ignored(false, "foo");
+	assert_is_ignored(false, "bar");
+	assert_is_ignored(true, "foo bar");
+}
+
+void test_attr_ignore__trailing_space(void)
+{
+	cl_git_rewritefile(
+		"attr/.gitignore",
+		"foo \n"
+		"bar  \n"
+	);
+
+	assert_is_ignored(true, "foo");
+	assert_is_ignored(false, "foo ");
+	assert_is_ignored(true, "bar");
+	assert_is_ignored(false, "bar ");
+	assert_is_ignored(false, "bar  ");
+}
+
+void test_attr_ignore__escaped_trailing_spaces(void)
+{
+	cl_git_rewritefile(
+		"attr/.gitignore",
+		"foo\\ \n"
+		"bar\\ \\ \n"
+		"baz \\ \n"
+		"qux\\  \n"
+	);
+
+	assert_is_ignored(false, "foo");
+	assert_is_ignored(true, "foo ");
+	assert_is_ignored(false, "bar");
+	assert_is_ignored(false, "bar ");
+	assert_is_ignored(true, "bar  ");
+	assert_is_ignored(true, "baz  ");
+	assert_is_ignored(false, "baz ");
+	assert_is_ignored(true, "qux ");
+	assert_is_ignored(false, "qux");
+	assert_is_ignored(false, "qux  ");
+}
+
 void test_attr_ignore__ignore_dir(void)
 {
 	cl_git_rewritefile("attr/.gitignore", "dir/\n");
-- 
cgit v1.2.1