Fixing issue #1997.

Changelog

@@ -5,6 +5,7 @@
   on Edges, Region, EdgePairs and Texts, delivering a pair of containers with 
   selected and unselected objects.
 * Bug: %GITHUB%/issues/1993 Tiling processor kept layout locks, causing DRC issues with "with_density"
+* Bug: %GITHUB%/issues/1997 Can not find a file in Open Recent menu (a string unescaping bug)
 * Bugfix: 'Save All' was not updating the dirty flag in the inactive tabs
 * Bugfix: Fixing a crash when editing PCell parameters while the macro editor is open
 * Bugfix: Fixed a potential Crash on "save all"

src/tl/tl/tlString.cc

@@ -702,7 +702,8 @@ inline char unescape_char (const char * &cp)
 {
   if (safe_isdigit (*cp)) {
     int c = 0;
-    while (*cp && safe_isdigit (*cp)) {
+    unsigned int n = 0;
+    while (*cp && safe_isdigit (*cp) && n++ < 3) {
       c = c * 8 + int (*cp - '0');
       ++cp;
     }

src/tl/unit_tests/tlStringTests.cc

@@ -504,6 +504,7 @@ TEST(10)
   EXPECT_EQ (escape_string ("'a\n\003"), "'a\\n\\003");
   EXPECT_EQ (escape_string ("'a\n\003"), "'a\\n\\003");
   EXPECT_EQ (unescape_string (escape_string ("'a\n\003")), "'a\n\003");
+  EXPECT_EQ (unescape_string (escape_string ("'a\n\0031")), "'a\n\0031");
 }
 
 TEST(11)