Fix crash with struct parameter assignment from function call. (#934)

Edge case that triggered an assert.

Author: lgritz

src/liboslcomp/codegen.cpp

@@ -998,15 +998,15 @@ ASTNode::codegen_struct_initializers (ref init, Symbol *sym,
             continue;
         }
 
-        if (paraminit) {
+        if (paraminit && nodetype() == variable_declaration_node) {
             // For parameter initialization, don't really generate ops if it
             // can be statically initialized.
             std::string out;
-            ASSERT (nodetype() == variable_declaration_node);
             ASTvariable_declaration *v = (ASTvariable_declaration *)this;
             if (v->param_default_literals (fieldsym, init.get(), out))
                 continue;
-
+        }
+        if (paraminit) {
             // Delineate and remember the init ops for this field individually
             m_compiler->codegen_method (fieldname);
             fieldsym->initbegin (m_compiler->next_op_label ());

testsuite/struct-return/ref/out.txt

@@ -1,4 +1,5 @@
 Compiled test.osl -> test.oso
+test struct param initialization: v2iparam = 19 20
 test struct return
 {2 3} + {10 20} = {12 23}
 square({2 3}) = {4 9}

testsuite/struct-return/test.osl

@@ -45,8 +45,11 @@ Complicated ugly ()
 
 
 shader
-test ()
+test (Vec2i v2iparam = Vec2i(19,20))
 {
+    printf ("test struct param initialization: v2iparam = %d %d\n",
+            v2iparam.x, v2iparam.y);
+    
     // Example of a function returning a struct in an inner scope
     Vec2i square (Vec2i a) {
         Vec2i r;