dovecot-2.2: liblib: Added str_unescape_next()

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.2/rev/9735c6fb7e39
changeset: 17112:9735c6fb7e39
user:      Timo Sirainen <tss at iki.fi>
date:      Wed Jan 15 16:44:04 2014 -0500
description:
liblib: Added str_unescape_next()

diffstat:

 src/lib/strescape.c      |  24 ++++++++++++++++++++++++
 src/lib/strescape.h      |   5 +++++
 src/lib/test-strescape.c |  13 ++++++++++++-
 3 files changed, 41 insertions(+), 1 deletions(-)

diffs (79 lines):

diff -r bdec18a1aa40 -r 9735c6fb7e39 src/lib/strescape.c
--- a/src/lib/strescape.c	Wed Jan 15 15:57:50 2014 -0500
+++ b/src/lib/strescape.c	Wed Jan 15 16:44:04 2014 -0500
@@ -77,6 +77,30 @@
 	return start;
 }
 
+int str_unescape_next(const char **str, const char **unescaped_r)
+{
+	const char *p;
+	char *escaped;
+	bool esc_found = FALSE;
+
+	for (p = *str; *p != '\0'; p++) {
+		if (*p == '"')
+			break;
+		else if (*p == '\\') {
+			if (p[1] == '\0')
+				return -1;
+			esc_found = TRUE;
+			p++;
+		}
+	}
+	if (*p != '"')
+		return -1;
+	escaped = p_strdup_until(unsafe_data_stack_pool, *str, p);
+	*str = p+1;
+	*unescaped_r = !esc_found ? escaped : str_unescape(escaped);
+	return 0;
+}
+
 void str_append_tabescaped(string_t *dest, const char *src)
 {
 	for (; *src != '\0'; src++) {
diff -r bdec18a1aa40 -r 9735c6fb7e39 src/lib/strescape.h
--- a/src/lib/strescape.h	Wed Jan 15 15:57:50 2014 -0500
+++ b/src/lib/strescape.h	Wed Jan 15 16:44:04 2014 -0500
@@ -12,6 +12,11 @@
 /* remove all '\' characters */
 char *str_unescape(char *str);
 
+/* Remove all '\' chars from str until '"' is reached and return the unescaped
+   string. *str is updated to point to the character after the '"'. Returns 0
+   if ok, -1 if '"' wasn't found. */
+int str_unescape_next(const char **str, const char **unescaped_r);
+
 /* For Dovecot's internal protocols: Escape \001, \t, \r and \n characters
    using \001. */
 const char *str_tabescape(const char *str);
diff -r bdec18a1aa40 -r 9735c6fb7e39 src/lib/test-strescape.c
--- a/src/lib/test-strescape.c	Wed Jan 15 15:57:50 2014 -0500
+++ b/src/lib/test-strescape.c	Wed Jan 15 16:44:04 2014 -0500
@@ -25,7 +25,7 @@
 		{ "\001\001\t\t\r\r\n\n", "\0011\0011\001t\001t\001r\001r\001n\001n" }
 	};
 	unsigned char buf[1 << CHAR_BIT];
-	const char *escaped, *tabstr;
+	const char *escaped, *tabstr, *unesc_str;
 	string_t *str;
 	unsigned int i;
 
@@ -57,6 +57,17 @@
 	}
 	test_end();
 
+	test_begin("str_unescape_next");
+	escaped = "foo\"bar\\\"b\\\\az\"plop";
+	test_assert(str_unescape_next(&escaped, &unesc_str) == 0);
+	test_assert(strcmp(unesc_str, "foo") == 0);
+	test_assert(str_unescape_next(&escaped, &unesc_str) == 0);
+	test_assert(strcmp(unesc_str, "bar\"b\\az") == 0);
+	test_assert(str_unescape_next(&escaped, &unesc_str) == -1);
+	escaped = "foo\\";
+	test_assert(str_unescape_next(&escaped, &unesc_str) == -1);
+	test_end();
+
 	test_begin("str_tabescape");
 	for (i = 0; i < N_ELEMENTS(tabesc); i++) {
 		test_assert(strcmp(str_tabunescape(t_strdup_noconst(tabesc[i].output)),