ifcfg-rh: refactor svUnescape()

Move the g_strchomp() inside svUnescape(). It is part of the
escaping process (although of course wrong to do, because
it accepts "FOO=  bar". That will be fixed later).

Thereby, change the signature to allow in the future
to do unescape without additional copy.

src/settings/plugins/ifcfg-rh/shvar.c

@@ -150,23 +150,31 @@ svEscape (const char *s, char **to_free)
 }
 
 /* remove escaped characters in place */
-void
-svUnescape (char *s)
+const char *
+svUnescape (const char *value, char **to_free)
 {
 	size_t len, idx_rd = 0, idx_wr = 0;
 	char c;
+	char *s;
+
+	nm_assert (value);
+	nm_assert (to_free);
+
+	/* TODO: avoid copying the string if there is nothing to do. */
+	s = g_strchomp (g_strdup (value));
+	*to_free = s;
 
 	len = strlen (s);
 	if (len < 2) {
 		if (s[0] == '\\')
 			s[0] = '\0';
-		return;
+		return s;
 	}
 
 	if ((s[0] == '"' || s[0] == '\'') && s[0] == s[len-1]) {
 		if (len == 2) {
 			s[0] = '\0';
-			return;
+			return s;
 		}
 		if (len == 3) {
 			if (s[1] == '\\') {
@@ -175,7 +183,7 @@ svUnescape (char *s)
 				s[0] = s[1];
 				s[1] = '\0';
 			}
-			return;
+			return s;
 		}
 		s[--len] = '\0';
 		idx_rd = 1;
@@ -184,10 +192,10 @@ svUnescape (char *s)
 		char *p = strchr (s, '\\');
 
 		if (!p)
-			return;
+			return s;
 		if (p[1] == '\0') {
 			p[0] = '\0';
-			return;
+			return s;
 		}
 		idx_wr = idx_rd = (p - s);
 	}
@@ -199,7 +207,7 @@ svUnescape (char *s)
 		if (c == '\\') {
 			if (s[idx_rd] == '\0') {
 				s[idx_wr] = '\0';
-				return;
+				return s;
 			}
 			s[idx_wr++] = s[idx_rd++];
 			continue;
@@ -207,6 +215,7 @@ svUnescape (char *s)
 		s[idx_wr++] = c;
 	}
 	s[idx_wr] = '\0';
+	return s;
 }
 
 /*****************************************************************************/
@@ -352,7 +361,7 @@ char *
 svGetValue (shvarFile *s, const char *key)
 {
 	const char *line_val;
-	char *value;
+	char *copied;
 
 	g_return_val_if_fail (s != NULL, NULL);
 	g_return_val_if_fail (key != NULL, NULL);
@@ -361,9 +370,8 @@ svGetValue (shvarFile *s, const char *key)
 	if (!line_val)
 		return NULL;
 
-	value = g_strchomp (g_strdup (line_val));
-	svUnescape (value);
-	return value;
+	line_val = svUnescape (line_val, &copied);
+	return copied ?: g_strdup (line_val);
 }
 
 /* Get the value associated with the key, and leave the current pointer

src/settings/plugins/ifcfg-rh/shvar.h

@@ -81,10 +81,7 @@ gboolean svWriteFile (shvarFile *s, int mode, GError **error);
 /* Close the file descriptor (if open) and free the shvarFile. */
 void svCloseFile (shvarFile *s);
 
-/* Return @s unmodified or an escaped string */
 const char *svEscape (const char *s, char **to_free);
-
-/* Unescape a string in-place */
-void svUnescape (char *s);
+const char *svUnescape (const char *s, char **to_free);
 
 #endif /* _SHVAR_H */

src/settings/plugins/ifcfg-rh/tests/test-ifcfg-rh.c

@@ -8695,50 +8695,13 @@ test_read_team_port_empty_config (void)
 	g_object_unref (connection);
 }
 
-/* Old algorithm for "remove escaped characters in place".
- *
- * This function is obsolete because it has O(n^2) runtime
- * complexity and got replaced. Keep it here for testing,
- * that both functions behave identical.
- **/
-static void
-svUnescape_On2 (char *s)
-{
-	int len, i;
-
-	len = strlen(s);
-	if (len >= 2 && (s[0] == '"' || s[0] == '\'') && s[0] == s[len-1]) {
-		i = len - 2;
-		if (i == 0)
-			s[0] = '\0';
-		else {
-			memmove(s, s+1, i);
-			s[i+1] = '\0';
-			len = i;
-		}
-	}
-	for (i = 0; i < len; i++) {
-		if (s[i] == '\\') {
-			memmove(s+i, s+i+1, len-(i+1));
-			len--;
-		}
-		s[len] = '\0';
-	}
-}
-
 static void
 test_svUnescape_assert (const char *str)
 {
-	char *s1 = g_strdup (str);
-	char *s2 = g_strdup (str);
+	gs_free char *to_free = NULL;
+	const char *s;
 
-	svUnescape (s1);
-	svUnescape_On2 (s2);
-
-	g_assert_cmpstr (s1, ==, s2);
-
-	g_free (s1);
-	g_free (s2);
+	s = svUnescape (str, &to_free);
 }
 
 static void