tr/// doesn't null-terminate the result in some situations

(from Gisle Aas)

p4raw-id: //depot/maint-5.6/perl@9551

doop.c

@@ -179,6 +179,7 @@ S_do_trans_complex(pTHX_ SV *sv)/* SPC - NOT OK */
 		s++;
 	    }
 	}
+	*d = '\0';
 	SvCUR_set(sv, d - dstart);
     }
     else { /* isutf8 */

t/op/tr.t

@@ -5,7 +5,7 @@ BEGIN {
     @INC = '../lib';
 }
 
-print "1..51\n";
+print "1..52\n";
 
 $_ = "abcdefghijklmnopqrstuvwxyz";
 
@@ -296,3 +296,8 @@ print "ok 50\n";
 ($a = v300.196.172.302.197.172) =~ tr/\xc4-\xc8/\x{12c}-\x{130}/;
 print "not " unless $a eq v300.300.172.302.301.172;
 print "ok 51\n";
+
+# misc
+($a = "R0_001") =~ tr/R_//d;
+print "not " if hex($a) != 1;
+print "ok 52\n";