Microsoft KB Archive/43530
Article ID: 43530
Article Last Modified on 11/21/2006
This article was previously published under Q43530
Choosing to UNLOAD a file while a Watch on a variable is set hangs the QB.EXE editor, requiring a warm or cold reboot if operating under MS-DOS. If you are running under OS/2, this choice hangs the DOS compatibility box. This problem does not occur when UNLOADing a file if a Watchpoint is set to watch an expression.
Microsoft has confirmed this to be a bug with QB.EXE in QuickBasic version 4.50. This problem was corrected in QBX.EXE in Microsoft Basic Professional Development System (PDS) version 7.00 (fixlist7.00).
To demonstrate this problem do the following:
- Type the following two lines in the QuickBasic editor:
B$ = "Hello"
- Save the file by choosing Save As from the File menu.
- Choose Add Watch from the Debug menu by pressing ALT+D and then pressing "A".
- Enter B$ as the expression to watch. Press ENTER.
- Choose Unload from the File menu by pressing ALT+F and then pressing "U". Press ENTER to UNLOAD the program. The editor will then display a menu prompting you to choose a new main module. If the editor does not hang, press ENTER again to choose "Untitled" as the main module. At this point the editor will hang, requiring a cold or warm reboot.
The following exact steps also cause QB.EXE version 4.50 to hang under similar circumstances:
- Start QuickBasic and load any Quick library:
QB /L QB.QLB
- Type the following and press ENTER:
PRINT "any text"
- Press the UP ARROW cursor key, thus placing the cursor under the "P" in PRINT.
- Press F9, thus placing a breakpoint on that line.
- Run the program by pressing SHIFT+F5.
- Select the Debug menu with ALT+D and press ENTER, thus choosing to set a watch variable.
- Type FRE("") as the watch variable and press ENTER.
- Press ALT+F+L (to select the Load File command), and press ESC.
- Press ALT+F+U (to select the Unload File command), and press ENTER.
- Press TAB, then the SPACE key, then ENTER, and the editor will be hung.
Additional query words: QuickBas BasicCom SR# S890410-127 buglist4.50 B_BasicCom