Avoid scribbling on the passed in command line string for -i in

moreswitches.

p4raw-id: //depot/perl@27451

diff --git a/perl.c b/perl.c
index 3cdca43..c152a39 100644 (file)
--- a/perl.c
+++ b/perl.c
@@ -3104,13 +3104,17 @@ Perl_moreswitches(pTHX_ char *s)
        return s+1;
        }
 #endif /* __CYGWIN__ */
-       PL_inplace = savepv(s+1);
-       for (s = PL_inplace; *s && !isSPACE(*s); s++)
-           ;
+       {
+           const char *start = ++s;
+           while (*s && !isSPACE(*s))
+               ++s;
+
+           PL_inplace = savepvn(start, s - start);
+       }
        if (*s) {
-           *s++ = '\0';
+           ++s;
            if (*s == '-')      /* Additional switches on #! line. */
-               s++;
+               s++;
        }
        return s;
     case 'I':  /* -I handled both here and in parse_body() */