[Freeciv-Dev] (PR#10611) valgrind warning in is_valid_start_pos

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=10611 >

==29760== Invalid read of size 4
==29760==    at 0x813C004: is_valid_start_pos (startpos.c:100)
==29760==    by 0x80C5EBA: rand_map_pos_filtered (map.c:1610)
==29760==    by 0x813CC37: create_start_positions (startpos.c:336)
==29760==    by 0x8137441: map_fractal_generate (mapgen.c:1081)
==29760==  Address 0x1BF177AC is 4 bytes before a block of size 124 alloc'd
==29760==    at 0x1B906EDD: malloc (vg_replace_malloc.c:131)
==29760==    by 0x804B512: fc_real_malloc (mem.c:79)
==29760==    by 0x813C248: initialize_isle_data (startpos.c:150)
==29760==    by 0x813C55F: create_start_positions (startpos.c:224)

This is my error, and easy to fix.

jason

? diff
? newtiles
? data/isotrident/selection.png
? data/isotrident/selection.spec
Index: server/generator/startpos.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/generator/startpos.c,v
retrieving revision 1.4
diff -u -r1.4 startpos.c
--- server/generator/startpos.c 15 Oct 2004 09:39:06 -0000      1.4
+++ server/generator/startpos.c 19 Oct 2004 04:47:28 -0000
@@ -96,16 +96,16 @@
 {
   const struct start_filter_data *pdata = dataptr;
   int i;
-  struct islands_data_type *island
-    = islands + islands_index[(int) map_get_continent(ptile)];
-  int cont_size;
+  struct islands_data_type *island;
+  int cont_size, cont = map_get_continent(ptile);
 
   /* Only start on certain terrain types. */  
   if (pdata->value[ptile->index] < pdata->min_value) {
       return FALSE;
   } 
 
-  if (islands[islands_index[(int) map_get_continent(ptile)]].starters == 0) {
+  assert(cont > 0);
+  if (islands[islands_index[cont]].starters == 0) {
     return FALSE;
   }
 
@@ -115,7 +115,8 @@
   }
 
   /* Don't start too close to someone else. */
-  cont_size = get_continent_size(map_get_continent(ptile));
+  cont_size = get_continent_size(cont);
+  island = islands + islands_index[cont];
   for (i = 0; i < pdata->count; i++) {
     struct tile *tile1 = map.start_positions[i].tile;