From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Wed, 10 Mar 2021 14:17:56 +0000 (+0100)
Subject: basic/extract-word: allow escape character to be escaped
X-Git-Tag: v248-rc3~2^2~4
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=76c4e48ee603593822b3076c4cf5b63768ec55e3;p=thirdparty%2Fsystemd.git

basic/extract-word: allow escape character to be escaped

With EXTRACT_UNESCAPE_SEPARATORS, backslash is used to escape the separator.
But it wasn't possible to insert the backslash itself. Let's allow this and
add test.
---

diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c
index 4e4e7e8ce93..06b813c031a 100644
--- a/src/basic/extract-word.c
+++ b/src/basic/extract-word.c
@@ -102,8 +102,8 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra
                                         else
                                                 sz += utf8_encode_unichar(s + sz, u);
                                 } else if ((flags & EXTRACT_UNESCAPE_SEPARATORS) &&
-                                           strchr(separators, **p))
-                                        /* An escaped separator char */
+                                           (strchr(separators, **p) || **p == '\\'))
+                                        /* An escaped separator char or the escape char itself */
                                         s[sz++] = c;
                                 else if (flags & EXTRACT_CUNESCAPE_RELAX) {
                                         s[sz++] = '\\';
diff --git a/src/test/test-extract-word.c b/src/test/test-extract-word.c
index f718556d399..217c600dac6 100644
--- a/src/test/test-extract-word.c
+++ b/src/test/test-extract-word.c
@@ -365,6 +365,18 @@ static void test_extract_first_word(void) {
         free(t);
         assert_se(p == NULL);
 
+        p = "a\\ b:c\\x";
+        assert_se(extract_first_word(&p, &t, ":", EXTRACT_UNESCAPE_SEPARATORS) == -EINVAL);
+
+        p = "a\\\\ b:c\\\\x";
+        assert_se(extract_first_word(&p, &t, ":", EXTRACT_UNESCAPE_SEPARATORS) == 1);
+        assert_se(streq(t, "a\\ b"));
+        free(t);
+        assert_se(extract_first_word(&p, &t, ":", EXTRACT_UNESCAPE_SEPARATORS) == 1);
+        assert_se(streq(t, "c\\x"));
+        free(t);
+        assert_se(p == NULL);
+
         p = "\\:";
         assert_se(extract_first_word(&p, &t, ":", EXTRACT_CUNESCAPE|EXTRACT_UNESCAPE_SEPARATORS) == 1);
         assert_se(streq(t, ":"));
@@ -386,6 +398,18 @@ static void test_extract_first_word(void) {
         free(t);
         assert_se(p == NULL);
 
+        p = "a\\ b:c\\x";
+        assert_se(extract_first_word(&p, &t, ":", EXTRACT_CUNESCAPE|EXTRACT_UNESCAPE_SEPARATORS) == -EINVAL);
+
+        p = "a\\\\ b:c\\\\x";
+        assert_se(extract_first_word(&p, &t, ":", EXTRACT_CUNESCAPE|EXTRACT_UNESCAPE_SEPARATORS) == 1);
+        assert_se(streq(t, "a\\ b"));
+        free(t);
+        assert_se(extract_first_word(&p, &t, ":", EXTRACT_CUNESCAPE|EXTRACT_UNESCAPE_SEPARATORS) == 1);
+        assert_se(streq(t, "c\\x"));
+        free(t);
+        assert_se(p == NULL);
+
         p = "\\:";
         assert_se(extract_first_word(&p, &t, ":", EXTRACT_CUNESCAPE) == -EINVAL);