[src/trunk]: src/lib/libedit Fix up bodgy code for printing completion matche...

[dholland <dholland%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4a106835744d
branches:  trunk
changeset: 759211:4a106835744d
user:      dholland <dholland%NetBSD.org@localhost>
date:      Thu Dec 02 04:35:17 2010 +0000

description:
Fix up bodgy code for printing completion matches; it used to sometimes
skip entries, print (null), run off the end of the array, or occasionally
receive SIGSEGV, and now will, hopefully at least, do none of that.

Based in part on the patch in PR 44183 from Sergio Acereda; I also
did some tidyup and fixed it to print top-to-bottom first like ls(1).

diffstat:

 lib/libedit/filecomplete.c |  57 +++++++++++++++++++++++++--------------------
 1 files changed, 32 insertions(+), 25 deletions(-)

diffs (95 lines):

diff -r f2e6b68e580e -r 4a106835744d lib/libedit/filecomplete.c
--- a/lib/libedit/filecomplete.c        Thu Dec 02 02:58:28 2010 +0000
+++ b/lib/libedit/filecomplete.c        Thu Dec 02 04:35:17 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: filecomplete.c,v 1.20 2010/11/15 21:24:31 christos Exp $       */
+/*     $NetBSD: filecomplete.c,v 1.21 2010/12/02 04:35:17 dholland Exp $       */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
 
 #include "config.h"
 #if !defined(lint) && !defined(SCCSID)
-__RCSID("$NetBSD: filecomplete.c,v 1.20 2010/11/15 21:24:31 christos Exp $");
+__RCSID("$NetBSD: filecomplete.c,v 1.21 2010/12/02 04:35:17 dholland Exp $");
 #endif /* not lint && not SCCSID */
 
 #include <sys/types.h>
@@ -338,39 +338,45 @@
 
 /*
  * Display list of strings in columnar format on readline's output stream.
- * 'matches' is list of strings, 'len' is number of strings in 'matches',
- * 'max' is maximum length of string in 'matches'.
+ * 'matches' is list of strings, 'num' is number of strings in 'matches',
+ * 'width' is maximum length of string in 'matches'.
+ *
+ * matches[0] is not one of the match strings, so the strings are
+ * matches[1] *through* matches[num].
  */
 void
-fn_display_match_list (EditLine *el, char **matches, size_t len, size_t max)
+fn_display_match_list (EditLine *el, char **matches, size_t num, size_t width)
 {
-       size_t i, idx, limit, count;
+       size_t line, lines, col, cols, thisguy;
        int screenwidth = el->el_term.t_size.h;
 
+       /* Ignore matches[0]. Avoid 1-based array logic below. */
+       matches++;
+
        /*
-        * Find out how many entries can be put on one line, count
-        * with two spaces between strings.
+        * Find out how many entries can be put on one line; count
+        * with one space between strings the same way it's printed.
         */
-       limit = screenwidth / (max + 2);
-       if (limit == 0)
-               limit = 1;
+       cols = screenwidth / (width + 1);
+       if (cols == 0)
+               cols = 1;
 
-       /* how many lines of output */
-       count = len / limit;
-       if (count * limit < len)
-               count++;
+       /* how many lines of output, rounded up */
+       lines = (num + cols - 1) / cols;
 
-       /* Sort the items if they are not already sorted. */
-       qsort(&matches[1], (size_t)(len - 1), sizeof(char *),
-           _fn_qsort_string_compare);
+       /* Sort the items. */
+       qsort(matches, num, sizeof(char *), _fn_qsort_string_compare);
 
-       idx = 1;
-       for(; count > 0; count--) {
-               int more = limit > 0 && matches[0];
-               for(i = 0; more; i++, idx++) {
-                       more = i < limit && matches[idx + 1];
-                       (void)fprintf(el->el_outfile, "%-*s%s", (int)max,
-                           matches[idx], more ? " " : "");
+       /*
+        * On the ith line print elements i, i+lines, i+lines*2, etc.
+        */
+       for (line = 0; line < lines; line++) {
+               for (col = 0; col < cols; col++) {
+                       thisguy = line + col * lines;
+                       if (thisguy >= num)
+                               break;
+                       (void)fprintf(el->el_outfile, "%s%-*s",
+                           col == 0 ? "" : " ", (int)width, matches[thisguy]);
                }
                (void)fprintf(el->el_outfile, "\n");
        }
@@ -492,6 +498,7 @@
                                if (match_len > maxlen)
                                        maxlen = match_len;
                        }
+                       /* matches[1] through matches[i-1] are available */
                        matches_num = i - 1;
                                
                        /* newline to get on next line from command line */