fix(renderer): shift part lines

Lots going on here. First, I managed to get a session that delivered
multiple permission requests at the same time. I still not sure why that
happened.

However, that code exposed a bug in the part line shifting code. The
code was only shift parts that started after the new line end when it
needed to look for parts up to the old line end for the part being
replaced.

Author: cameronr

lua/opencode/ui/renderer.lua

@@ -24,6 +24,7 @@ function M.reset()
 
   state.messages = {}
   state.last_user_message = nil
+  state.current_permission = nil
 end
 
 ---Set up all subscriptions, for both local and server events
@@ -328,6 +329,8 @@ function M._replace_part_in_buffer(part_id, formatted_data)
 
   output_window.set_lines(new_lines, cached.line_start, cached.line_end + 1)
 
+  -- we need the old line_end to know where to start looking for parts to shift
+  local old_line_end = cached.line_end
   cached.line_end = cached.line_start + new_line_count - 1
 
   output_window.set_extmarks(formatted_data.extmarks, cached.line_start)
@@ -344,10 +347,7 @@ function M._replace_part_in_buffer(part_id, formatted_data)
     end
   end
 
-  local line_delta = new_line_count - old_line_count
-  if line_delta ~= 0 then
-    M._shift_parts_and_actions(cached.line_end + 1, line_delta)
-  end
+  M._shift_parts_and_actions(old_line_end + 1, new_line_count - old_line_count)
 
   return true
 end
@@ -583,6 +583,19 @@ function M.on_permission_updated(properties)
     return
   end
 
+  local prev_permission = state.current_permission
+  state.current_permission = nil
+
+  if prev_permission and prev_permission.id ~= permission.id then
+    -- we got a permission request while we had an existing one?
+    vim.notify('Two pending permissions? existing: ' .. prev_permission.id .. ' new: ' .. permission.id)
+    -- rerender previous part to remove old permission
+    local prev_perm_part_id = M._find_part_by_call_id(prev_permission.callID)
+    if prev_perm_part_id then
+      M._rerender_part(prev_perm_part_id)
+    end
+  end
+
   state.current_permission = permission
 
   local part_id = M._find_part_by_call_id(permission.callID)