COMMON: fix backslash escape regression

Author: chrisws

samples/distro-examples/tests/strings.bas

@@ -176,8 +176,8 @@ if expect != seq(0, 2*pi, 360/15+1) then throw "SEQ error"
 
 s="Hello\033There"
 if (27 != asc(mid(s, 6, 1))) then throw "err"
-s="This\033T\ha\t\The\"Other"
-rem ThisnT\ha\t\The"Other - non escaping '\' should appear verbatim
-if len(s) != 21 then throw "escape error"
-s="Hello\03There"
-if len(s) != 13 then throw "escape error"
+rem Non escaping '\' should appear verbatim
+s= "a\c\e"
+if mid(s, 2, 1) != "\\" then throw s
+if mid(s, 4, 1) != "\\" then throw s
+

src/common/scan.c

@@ -3920,7 +3920,7 @@ char *comp_load(const char *file_name) {
 }
 
 const char *format_numeric_text(const char *str, char **output) {
-  const char *result = str;
+  const char *result = str + 1;
   int value = 0;
   int digits = 0;
 
@@ -3934,7 +3934,7 @@ const char *format_numeric_text(const char *str, char **output) {
     **output = value;
   } else {
     **output = *str;
-    result = str;
+    result = str + 1;
   }
 
   (*output)++;
@@ -4151,7 +4151,7 @@ char *comp_format_text(const char *source) {
         // new line auto-ends the quoted string
         quotes = !quotes;
       } else if (*p == '\\') {
-        p = format_numeric_text(p + 1, &ps);
+        p = format_numeric_text(p, &ps);
         continue;
       }
       *ps++ = *p++;