[caravan] search within containers on trade screen

changelog.txt

@@ -35,6 +35,7 @@ Template for new versions:
 
 ## Misc Improvements
 - `combine`: prevent stack sizes from growing beyond quantities that you would normally see in vanilla gameplay
+- `caravan`: enable searching within containers in trade screen when in "trade bin with contents" mode
 
 ## Removed
 

internal/caravan/common.lua

@@ -25,6 +25,15 @@ function make_search_key(str)
     return table.concat(words, ' ')
 end
 
+function make_container_search_key(item, desc)
+    local words = {}
+    add_words(words, desc)
+    for _, contained_item in ipairs(dfhack.items.getContainedItems(item)) do
+        add_words(words, get_item_description(contained_item))
+    end
+    return table.concat(words, ' ')
+end
+
 local function get_broker_skill()
     local broker = dfhack.units.getUnitByNobleRole('broker')
     if not broker then return 0 end

internal/caravan/trade.lua

@@ -398,13 +398,19 @@ function Trade:cache_choices(list_idx, trade_bins)
             parent_data.has_requested = parent_data.has_requested or is_requested
             parent_data.ethical = parent_data.ethical and is_ethical
         end
+        local is_container = df.item_binst:is_instance(item)
+        local search_key
+        if (trade_bins and is_container) or item:isFoodStorage() then
+            search_key = common.make_container_search_key(item, desc)
+        else
+            search_key = common.make_search_key(desc)
+        end
         local choice = {
-            search_key=common.make_search_key(desc),
+            search_key=search_key,
             icon=curry(get_entry_icon, data),
             data=data,
             text=make_choice_text(data.value, desc),
         }
-        local is_container = df.item_binst:is_instance(item)
         if not data.update_container_fn then
             table.insert(trade_bins_choices, choice)
         end