From dddff0f4507f297c0bd36d77caf5180be7f56acd Mon Sep 17 00:00:00 2001
From: Rangi <remy.oukaour+rangi42@gmail.com>
Date: Fri, 12 Feb 2021 15:54:15 -0500
Subject: [PATCH] Cannot start a new section that's already on the stack

This is only relevant for FRAGMENT or UNION sections, since
normal ones would fail with "Section already defined previously".

Fixes #730
---
 src/asm/section.c               | 12 ++++++------
 test/asm/new-pushed-section.asm |  7 +++++++
 test/asm/new-pushed-section.err |  2 ++
 test/asm/new-pushed-section.out |  0
 4 files changed, 15 insertions(+), 6 deletions(-)
 create mode 100644 test/asm/new-pushed-section.asm
 create mode 100644 test/asm/new-pushed-section.err
 create mode 100644 test/asm/new-pushed-section.out

diff --git a/src/asm/section.c b/src/asm/section.c
index e77018ea..44a816f2 100644
--- a/src/asm/section.c
+++ b/src/asm/section.c
@@ -87,15 +87,10 @@ static inline void reserveSpace(uint32_t delta_size)
 
 struct Section *out_FindSectionByName(const char *name)
 {
-	struct Section *sect = pSectionList;
-
-	while (sect) {
+	for (struct Section *sect = pSectionList; sect; sect = sect->next) {
 		if (strcmp(name, sect->name) == 0)
 			return sect;
-
-		sect = sect->next;
 	}
-
 	return NULL;
 }
 
@@ -376,6 +371,11 @@ void out_NewSection(char const *name, uint32_t type, uint32_t org,
 	if (currentLoadSection)
 		fatalerror("Cannot change the section within a `LOAD` block\n");
 
+	for (struct SectionStackEntry *stack = sectionStack; stack; stack = stack->next) {
+		if (stack->section && !strcmp(name, stack->section->name))
+			fatalerror("Section '%s' is already on the stack\n", name);
+	}
+
 	struct Section *sect = getSection(name, type, org, attribs, mod);
 
 	changeSection();
diff --git a/test/asm/new-pushed-section.asm b/test/asm/new-pushed-section.asm
new file mode 100644
index 00000000..c94bcda3
--- /dev/null
+++ b/test/asm/new-pushed-section.asm
@@ -0,0 +1,7 @@
+SECTION FRAGMENT "A", ROM0
+	db 1
+PUSHS
+SECTION FRAGMENT "A", ROM0
+	db 2
+POPS
+	db 3
diff --git a/test/asm/new-pushed-section.err b/test/asm/new-pushed-section.err
new file mode 100644
index 00000000..8a1b9beb
--- /dev/null
+++ b/test/asm/new-pushed-section.err
@@ -0,0 +1,2 @@
+FATAL: new-pushed-section.asm(4):
+    Section 'A' is already on the stack
diff --git a/test/asm/new-pushed-section.out b/test/asm/new-pushed-section.out
new file mode 100644
index 00000000..e69de29b