From 0f2b3aca24f4e3ea6da8a0a8b0c719b5bc55e8fb Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Tue, 18 Feb 2020 15:46:55 -0500
Subject: [PATCH] zasm: allow zasm to omit its 3rd argument

A bug in rdWS made zasm error out when omiting its 3rd argument.

fixes #90
---
 apps/lib/util.asm            |  8 +++---
 emul/shell/user.h            |  1 -
 tests/unit/test_lib_util.asm | 55 ++++++++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 5 deletions(-)
 create mode 100644 tests/unit/test_lib_util.asm

diff --git a/apps/lib/util.asm b/apps/lib/util.asm
index 0dda00f..386f990 100644
--- a/apps/lib/util.asm
+++ b/apps/lib/util.asm
@@ -20,10 +20,10 @@ toWS:
 ; Set Z if non-WS found, unset if end-of-string.
 rdWS:
 	ld	a, (hl)
-	call	isWS
-	jr	nz, .ok
 	cp	0x01	; if a is null, carries and unsets z
 	ret	c
+	call	isWS
+	jr	nz, .ok
 	inc	hl
 	jr	rdWS
 .ok:
@@ -97,8 +97,8 @@ strlen:
 	ld	c, a
 	cpir		; advances HL to the char after the null
 .found:
-	; How many char do we have? We have strlen=(NEG BC)-1, since BC started 
-	; at 0 and decreased at each CPIR loop. In this routine, 
+	; How many char do we have? We have strlen=(NEG BC)-1, since BC started
+	; at 0 and decreased at each CPIR loop. In this routine,
 	; we stay in the 8-bit realm, so C only.
 	add 	hl, bc
 	sub	c
diff --git a/emul/shell/user.h b/emul/shell/user.h
index 47aac6d..d4a758d 100644
--- a/emul/shell/user.h
+++ b/emul/shell/user.h
@@ -1,4 +1,3 @@
-.equ    SHELL_RAMSTART  0x4100
 .equ    USER_CODE       0x4200  ; in sync with glue.asm
 
 ; *** JUMP TABLE ***
diff --git a/tests/unit/test_lib_util.asm b/tests/unit/test_lib_util.asm
new file mode 100644
index 0000000..f1d28aa
--- /dev/null
+++ b/tests/unit/test_lib_util.asm
@@ -0,0 +1,55 @@
+jp	test
+
+.inc "ascii.h"
+.inc "core.asm"
+.equ	STDIO_RAMSTART	RAMSTART
+.inc "stdio.asm"
+.inc "common.asm"
+.inc "lib/ari.asm"
+.inc "lib/fmt.asm"
+.inc "lib/util.asm"
+
+test:
+	ld	sp, 0xffff
+
+	call	testRdWS
+
+	; success
+	xor	a
+	halt
+
+testRdWS:
+	ld	hl, .allGood
+	ld	ix, .testGood
+	call	testList
+	ld	hl, .allBad
+	ld	ix, .testBad
+	jp	testList
+
+.testGood:
+	call	rdWS
+	jp	assertZ
+
+.testBad:
+	call	rdWS
+	jp	assertNZ
+
+; Strings ending with a non-WS, and thus yielding Z
+.g1:
+	.db	" X", 0
+.g2:
+	.db	"X", 0
+
+.allGood:
+	.dw	.g1, .g2, 0
+
+; Strings ending with a WS, and thus yielding NZ
+.b1:
+	.db	0
+.b2:
+	.db	" ", 0
+
+.allBad:
+	.dw	.b1, .b2, 0
+
+RAMSTART: