fix: crash when converting some from byte to bool

Author: boriel

src/arch/z80/backend/generic.py

@@ -341,6 +341,9 @@ def _cast(ins: Quad):
 
     xsB = sB = YY_TYPES[tB]  # Type sizes
 
+    if tA in ("u8", "i8") and tB == "bool":
+        return []  # bytes are booleans already (0 = False, not 0 = True)
+
     output = []
     if tA in ("u8", "i8", "bool"):
         output.extend(Bits8.get_oper(ins[4]))

tests/functional/arch/zx48k/bool_crash.asm

@@ -0,0 +1,55 @@
+	org 32768
+.core.__START_PROGRAM:
+	di
+	push ix
+	push iy
+	exx
+	push hl
+	exx
+	ld hl, 0
+	add hl, sp
+	ld (.core.__CALL_BACK__), hl
+	ei
+	jp .core.__MAIN_PROGRAM__
+.core.__CALL_BACK__:
+	DEFW 0
+.core.ZXBASIC_USER_DATA:
+	; Defines USER DATA Length in bytes
+.core.ZXBASIC_USER_DATA_LEN EQU .core.ZXBASIC_USER_DATA_END - .core.ZXBASIC_USER_DATA
+	.core.__LABEL__.ZXBASIC_USER_DATA_LEN EQU .core.ZXBASIC_USER_DATA_LEN
+	.core.__LABEL__.ZXBASIC_USER_DATA EQU .core.ZXBASIC_USER_DATA
+_pldx:
+	DEFB 00
+.core.ZXBASIC_USER_DATA_END:
+.core.__MAIN_PROGRAM__:
+	ld hl, 0
+	ld b, h
+	ld c, l
+.core.__END_PROGRAM:
+	di
+	ld hl, (.core.__CALL_BACK__)
+	ld sp, hl
+	exx
+	pop hl
+	exx
+	pop iy
+	pop ix
+	ei
+	ret
+_ReadKeys:
+	push ix
+	ld ix, 0
+	add ix, sp
+	pop af
+	ld hl, (_pldx - 1)
+	or h
+	jp z, .LABEL.__LABEL1
+	ld a, 1
+	ld (_pldx), a
+.LABEL.__LABEL1:
+_ReadKeys__leave:
+	ld sp, ix
+	pop ix
+	ret
+	;; --- end of user code ---
+	END

tests/functional/arch/zx48k/bool_crash.bas

@@ -0,0 +1,7 @@
+dim pldx as ubyte
+
+sub ReadKeys()
+    if pldx or (pldx and %1) then
+        pldx = 1
+    endif
+end sub