[RFA] symtab.c: Set "first" to zero.

[dje@google.com (Doug Evans)]

Hi.

The "first" argument to filename_seen is used to control the
initialization of the data structure used to track whether
a file name has been seen yet.
But these two routines don't set it to zero after calling
filename_seen so the data structure is continually reinitialized
resulting in duplicate names in the output.
The completion machinery does its own duplicate elimination so
the effect of this bug is hidden.  I just noticed it while browsing the code.

Ok to check in?

2012-07-09  Doug Evans  <dje@google.com>

	* symtab.c (maybe_add_partial_symtab_filename): Set "first" to zero
	after calling filename_seen.
	(make_source_files_completion_list): Ditto.

Index: symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.316
diff -u -p -r1.316 symtab.c
--- symtab.c	29 Jun 2012 22:46:45 -0000	1.316
+++ symtab.c	9 Jul 2012 23:46:45 -0000
@@ -4576,6 +4576,7 @@ maybe_add_partial_symtab_filename (const
 	  && filename_ncmp (base_name, data->text, data->text_len) == 0)
 	add_filename_to_list (base_name, data->text, data->word, data->list);
     }
+  *data->first = 0;
 }
 
 /* Return a vector of all source files whose names begin with matching
@@ -4623,6 +4624,7 @@ make_source_files_completion_list (char 
 	      && filename_ncmp (base_name, text, text_len) == 0)
 	    add_filename_to_list (base_name, text, word, &list);
 	}
+      first = 0;
     }
 
   datum.first = &first;