sed: allow comments, braces after y///

sed-4.4 and earlier rejected the following:
  $ sed 'y/1/a/ #f'
  sed: -e expression #1, char 8: extra characters after command

See https://bugs.gnu.org/22460 .

* sed/compile.c (compile_program): Handle comments, braces after 'y' command.
* NEWS: Mention it.

NEWS

@@ -2,6 +2,11 @@ GNU sed NEWS                                    -*- outline -*-
 
 * Noteworthy changes in release ?.? (????-??-??) [?]
 
+** Bug fixes
+
+  sed no longer rejects comments and closing braces after y/// commands.
+  [Bug existed at least since sed-3.02]
+
 
 * Noteworthy changes in release 4.4 (2017-02-03) [stable]
 

sed/compile.c

@@ -1348,7 +1348,10 @@ compile_program(struct vector *vector)
                 cur_cmd->x.translate = translate;
               }
 
-            if ((ch = in_nonblank()) != EOF && ch != '\n' && ch != ';')
+            ch = in_nonblank();
+            if (ch == CLOSE_BRACE || ch == '#')
+              savchar(ch);
+            else if (ch != EOF && ch != '\n' && ch != ';')
               bad_prog(_(EXCESS_JUNK));
 
             free_buffer(b);