Bug#937

myisamchk.c:
  help text clarified
mi_check.c:
  allow one to "analyze" empty table :)

myisam/mi_check.c

@@ -3562,11 +3562,12 @@ int update_state_info(MI_CHECK *param, MI_INFO *info,uint update)
     uint i, key_parts= mi_uint2korr(share->state.header.key_parts);
     share->state.rec_per_key_rows=info->state->records;
     share->state.changed&= ~STATE_NOT_ANALYZED;
-    for (i=0; i<key_parts; i++)
-    {
-      if (!(share->state.rec_per_key_part[i]=param->rec_per_key_part[i]))
-        share->state.changed|= STATE_NOT_ANALYZED;
-    }
+    if (info->state->records)
+      for (i=0; i<key_parts; i++)
+      {
+        if (!(share->state.rec_per_key_part[i]=param->rec_per_key_part[i]))
+          share->state.changed|= STATE_NOT_ANALYZED;
+      }
   }
   if (update & (UPDATE_STAT | UPDATE_SORT | UPDATE_TIME | UPDATE_AUTO_INC))
   {

myisam/myisamchk.c

@@ -357,11 +357,15 @@ static void usage(void)
   -e, --extend-check  Check the table VERY throughly.  Only use this in\n\
                       extreme cases as myisamchk should normally be able to\n\
                       find out if the table is ok even without this switch\n\
-  -F, --fast	      Check only tables that haven't been closed properly\n\
-  -C, --check-only-changed\n\
-		      Check only tables that have changed since last check\n\
+  -F, --fast          Check only tables that haven't been closed properly.\n\
+                      It also applies to other requested actions (e.g. --analyze\n\
+                      will be ignored if the table is already analyzed).\n\
   -f, --force         Restart with '-r' if there are any errors in the table.\n\
 		      States will be updated as with '--update-state'\n\
+  -C, --check-only-changed\n\
+                      Check only tables that have changed since last check.\n\
+                      It also applies to other requested actions (e.g. --analyze\n\
+                      will be ignored if the table is already analyzed).\n\
   -i, --information   Print statistics information about table that is checked\n\
   -m, --medium-check  Faster than extend-check, but only finds 99.99% of\n\
 		      all errors.  Should be good enough for most cases\n\