NASM local variables - are they, in fact, global macros? - macros

Question

I've been using the %local directive in NASM to define local variables and thus avoid typing [ebp - 8], [ebp - 24] etc. all the time.
However, I noticed that a local variable defined in one function between the preprocessor context %push and %pop is still available in the rest of the code, which may result in unexpected parsing errors.
Here, I've written a minimal example demonstrating the problem:
struc Rect
.left resd 1
.top resd 1
.width resd 1
.height resd 1
endstruc
%define RECT(x) g_rect + Rect. %+ x
segment .bss
g_rect resd 4
segment .text
; ================================================
function1:
%push
%stacksize flat
%assign %$localsize 0
%local width:dword ; defines local var "width"
push ebp
mov ebp, esp
sub esp, 4
pusha
; ...
popa
leave
ret
%pop
; ================================================
function2:
push ebp
mov ebp, esp
pusha
; ...
mov eax, RECT(height) ; OK
mov ebx, RECT(width) ; Parse error
; ...
popa
leave
ret
The exact error is:
nasm -f elf -d ELF_TYPE -g test.asm
test.asm:42: error: comma, colon, decorator or end of line expected after operand
Obviously, it happens because width is getting substituted with something else, and if I remove the local param definition, the problem goes away.
As you can see, the variable width is still available after the %pop. This doesn't look very local to me! I'd expect NASM to undefine width when the %pop is executed.
Is there a way to use %local but avoid these leaking macros? At the moment they act as a simple %define statement which is confusing.