GH-123996: Explicitly mark 'self_or_null' as an array of size 1 to ensure that it is kept in memory for calls (GH-124003)

2 files changed, 15 insertions, 5 deletions

diff --git a/Tools/cases_generator/generators_common.py b/Tools/cases_generator/generators_common.py
index dd4057c..2f8fcce 100644
--- a/Tools/cases_generator/generators_common.py
+++ b/Tools/cases_generator/generators_common.py
@@ -165,9 +165,12 @@ class Emitter:
             if var.name == "unused" or var.name == "null" or var.peek:
                 continue
             if var.size:
-                self.out.emit(f"for (int _i = {var.size}; --_i >= 0;) {{\n")
-                self.out.emit(f"PyStackRef_CLOSE({var.name}[_i]);\n")
-                self.out.emit("}\n")
+                if var.size == "1":
+                    self.out.emit(f"PyStackRef_CLOSE({var.name}[0]);\n")
+                else:
+                    self.out.emit(f"for (int _i = {var.size}; --_i >= 0;) {{\n")
+                    self.out.emit(f"PyStackRef_CLOSE({var.name}[_i]);\n")
+                    self.out.emit("}\n")
             elif var.condition:
                 if var.condition == "1":
                     self.out.emit(f"PyStackRef_CLOSE({var.name});\n")
diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index 34bf597..de4d900 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -164,6 +164,8 @@ class StackOffset:
 class StackError(Exception):
     pass
 
+def array_or_scalar(var: StackItem | Local) -> str:
+    return "array" if var.is_array() else "scalar"
 
 class Stack:
     def __init__(self) -> None:
@@ -177,10 +179,15 @@ class Stack:
         indirect = "&" if var.is_array() else ""
         if self.variables:
             popped = self.variables.pop()
+            if var.is_array() ^ popped.is_array():
+                raise StackError(
+                    f"Array mismatch when popping '{popped.name}' from stack to assign to '{var.name}'. "
+                    f"Expected {array_or_scalar(var)} got {array_or_scalar(popped)}"
+                )
             if popped.size != var.size:
                 raise StackError(
-                    f"Size mismatch when popping '{popped.name}' from stack to assign to {var.name}. "
-                    f"Expected {var.size} got {popped.size}"
+                    f"Size mismatch when popping '{popped.name}' from stack to assign to '{var.name}'. "
+                    f"Expected {var_size(var)} got {var_size(popped.item)}"
                 )
             if var.name in UNUSED:
                 if popped.name not in UNUSED and popped.name in self.defined: