added a lua-test

New lua-test for the bug concerning the minskill for castle-stages.
(#1859)

scripts/tests/e3/castles.lua

@@ -50,3 +50,26 @@ function test_build_packice()
     process_orders()
     assert_equal(nil, u.building)
 end
+
+function test_build_castle_stages()
+    local r = region.create(0,0, "plain")
+    local f = faction.create("castle@eressea.de", "human", "de")
+    local u = unit.create(f, r, 1000)
+    local b = building.create(r, "castle")
+
+    u:add_item("stone", 1000)
+
+    u:set_skill("building", 1)
+    u:clear_orders()
+
+    u:add_order("MACHE BURG " .. itoa36(b.id))
+    process_orders()
+    assert_equal(10, b.size)
+    
+    u:set_skill("building", 3)
+    u:clear_orders()
+    
+    u:add_order("MACHE BURG " .. itoa36(b.id))
+    process_orders()
+    assert_equal(250, b.size)
+end

src/kernel/build.c

@@ -522,7 +522,9 @@ int build(unit * u, const construction * ctype, int completed, int want)
 
         if (basesk < type->minskill) {
             if (made == 0)
-                return ELOWSKILL;       /* not good enough to go on */
+                return ELOWSKILL;
+            else
+                return made;        /* not good enough to go on */
         }
 
         /* n = maximum buildable size */