From f18de90868cb4c3e4009eed363d20ca2a667a303 Mon Sep 17 00:00:00 2001
From: Kwarde <kevin@kwarde.com>
Date: Sun, 27 Jul 2025 21:17:59 +0200
Subject: [PATCH] 1) REALLY fix strcat crash (git restored wrong file in
 previous commit) 2) fopen: less labels ffs

---
 src/file.asm   | 17 +++++++----------
 src/string.asm |  6 ++++++
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/file.asm b/src/file.asm
index 0645407..f92a8f5 100644
--- a/src/file.asm
+++ b/src/file.asm
@@ -97,7 +97,7 @@ fgetmod:
 ;	rdi	(arg) Pointer to string holding (path+)file name
 ;	rsi	Mode to open the file with (see description above)
 fopen:
-	%macro createFile 1
+	%macro createFile 0
 	push	rdi
 	push	rsi
 	call	fexist
@@ -105,7 +105,7 @@ fopen:
 	pop	rdi
 	test	rax, 1
 	jz	%%createFile
-	jmp	%1
+	jmp	%%cnt
 	%%createFile:
 	push	rsi
 	push	rdi
@@ -119,6 +119,7 @@ fopen:
 	syscall
 	pop	rdi
 	pop	rsi
+	%%cnt:
 	%endmacro
 	;;;
 	;;; ENTRY
@@ -144,26 +145,22 @@ fopen:
 	mov	rsi, O_RDONLY
 	jmp	.open
 	.setMode_w:
-		createFile .open_w
-	.open_w:
+		createFile
 	mov	rsi, O_WRONLY | O_TRUNC
 	jmp	.open
 	.setMode_a:
-		createFile .open_a
-	.open_a:
+		createFile
 	mov	rsi, O_WRONLY | O_APPEND
 	jmp	.open
 	.setMode_R:
 	mov	rsi, O_RDWR
 	jmp	.open
 	.setMode_W:
-		createFile .open_W
-	.open_W:
+		createFile
 	mov	rsi, O_RDWR | O_TRUNC
 	jmp	.open
 	.setMode_A:
-		createFile .open_A
-	.open_A:
+		createFile
 	mov	rsi, O_RDWR | O_APPEND
 	jmp	.open
 
diff --git a/src/string.asm b/src/string.asm
index b5ba02a..920b594 100644
--- a/src/string.asm
+++ b/src/string.asm
@@ -66,10 +66,12 @@ strcpy:
 ;	r8*	Backup for rdi (point to start of dest)
 ;	r9*	Backup for rsi
 ;	r10*	Backup for rdi (point to end of dest)
+;	r11*	Backup for strlen(dest)
 strcat:
 	mov	r8, rdi
 	mov	r9, rsi
 	call	strlen
+	mov	r11, rax
 	sub	rdx, rax
 	dec	rdi
 	mov	r10, rdi
@@ -78,13 +80,17 @@ strcat:
 	cmp	rax, rdx
 	jb	.copy
 	dec	rdx
+
 	.copy:
+	cmp	rdx, r11
+	jle	.quit
 	mov	rcx, rdx
 	mov	rsi, r9
 	mov	rdi, r10
 	cld
 	rep	movsb
 	mov	byte [rdi], EOS
+	.quit:
 	mov	rax, r8
 	ret