[7760] avoid null dereference for displaying matches

[gavinsmith0123]

Revision: 7760
          http://svn.sv.gnu.org/viewvc/?view=rev&root=texinfo&revision=7760
Author:   gavin
Date:     2017-04-27 14:06:21 -0400 (Thu, 27 Apr 2017)
Log Message:
-----------
avoid null dereference for displaying matches

Modified Paths:
--------------
    trunk/ChangeLog
    trunk/info/display.c

Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog     2017-04-26 21:02:12 UTC (rev 7759)
+++ trunk/ChangeLog     2017-04-27 18:06:21 UTC (rev 7760)
@@ -1,3 +1,10 @@
+2017-04-27  Gavin Smith  <address@hidden>
+
+       * info/display.c (display_process_line): Avoid possibly
+       dereferencing a null pointer.  This could happen if the 
+       'match-rendition' value was set to an empty value in .infokey.
+       Report by Benno Schulenberg.
+
 2017-04-26  Benno Schulenberg  <address@hidden>  (tiny change)
 
        * info/session.c (info_tree_search): Mark a message for 

Modified: trunk/info/display.c
===================================================================
--- trunk/info/display.c        2017-04-26 21:02:12 UTC (rev 7759)
+++ trunk/info/display.c        2017-04-27 18:06:21 UTC (rev 7760)
@@ -357,7 +357,7 @@
         break;
       cur_ptr = mbi_cur_ptr (iter);
 
-      if (matches_ready (matches)
+      if (matches && matches_ready (matches)
           && !at_end_of_matches (matches, match_index))
         {
           int was_in_match = in_match;