3052 - make edit/ render functions higher-order

This required the fix of 3051 to first-class recipe support, and will
next enable us to keep the cursor from moving in response to resize
events.

1 files changed, 4 insertions, 0 deletions

diff --git a/060recipe.cc b/060recipe.cc
index d60badb6..b7d1e71f 100644
--- a/060recipe.cc
+++ b/060recipe.cc
@@ -64,6 +64,10 @@ case CALL: {
     trace("trace") << "indirect 'call': incrementing callstack depth to " << Trace_stream->callstack_depth << end();
     assert(Trace_stream->callstack_depth < 9000);  // 9998-101 plus cushion
   }
+  if (!ingredients.at(0).at(0)) {
+    raise << maybe(current_recipe_name()) << "tried to call empty recipe in '" << to_string(current_instruction()) << "'" << end();
+    break;
+  }
   const instruction& caller_instruction = current_instruction();
   Current_routine->calls.push_front(call(ingredients.at(0).at(0)));
   ingredients.erase(ingredients.begin());  // drop the callee