DlgBox* with 2lines arguments will accept both "" and NULL for a blank line

git-svn-id: svn://svn.cc65.org/cc65/trunk@2107 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/doc/geos.sgml b/doc/geos.sgml
index a49b4d88d91b65ee9dcbe72c11e1aa3b34dccf78..efbb6e19a415daf68b679f40f9370aa191fd77fc 100644 (file)
--- a/doc/geos.sgml
+++ b/doc/geos.sgml
@@ -499,6 +499,7 @@ GEOS application.
 <p>
 These function show two lines of text in standard-sized DialogBox. You can read the code of
 pressed icon from return value. E.g. for <tt/DlgBoxYesNo/ it can only be <tt/YES/ or <tt/NO/.
+You can pass an empty string or NULL to get a blank line.
 
 <sect3>DlgBoxGetString
 <p>

diff --git a/libsrc/geos/dlgbox/dbget2lines.s b/libsrc/geos/dlgbox/dbget2lines.s
index 1258dbb48cfd815924fc24313550f814862d9fc2..96440987d447c2e28195d143159281d1f604baa0 100644 (file)
--- a/libsrc/geos/dlgbox/dbget2lines.s
+++ b/libsrc/geos/dlgbox/dbget2lines.s
@@ -1,6 +1,6 @@
 
 ;
-; Maciej 'YTM/Alliance' Witkowiak
+; Maciej 'YTM/Elysium' Witkowiak
 ;
 ; 25.12.99
 
@@ -8,10 +8,30 @@
            .importzp ptr3,ptr4
            .import popax
 
+.code
+
 DB_get2lines:
-           sta ptr4
+           sta ptr4            ; fetch line 2
            stx ptr4+1
            jsr popax
-           sta ptr3
+           sta ptr3            ; fetch line 1
            stx ptr3+1
-           rts
+           ldx ptr3
+           jsr checknull
+           ldx ptr4
+           jmp checknull
+
+checknull:
+           lda $0,x
+           ora $1,x
+           bne cn_end
+           lda #<nullstring
+           sta $0,x
+           lda #>nullstring
+           sta $1,x
+cn_end:            rts
+
+.rodata
+
+nullstring:
+           .byte 0