howard@cpocd2.UUCP (Howard A. Landman) (12/01/87)
I seem to have discovered a small, relatively harmless bug in HyperCard.
To reproduce it, try this:
Make a new stack StackA. In the background for StackA, put a large field.
Make a card in StackA called CardA1.
Make a new stack StackB. Make a card in StackB called CardB1. On CardB1,
put an icon button (for example a rolodex card icon). Make sure that the
box for the button is much larger than the icon, and that a lot of it
overlaps the bounding box of the background field in the other stack.
This should be a card button, not a background button.
Double click on the button, and use the "Link to ..." button to link it
to CardA1.
Make a new card in StackB called CardB2. It won't yet have a button. Go
to CardB1, select the button there, and copy it with command-C. Go back
to CardB2, and paste the button with command-V.
Double click on the button in CardB2, and press the "Link to ..." button.
What you want is to link it to a new card in StackA. Get to StackA by
clicking the button in CardB2, which brings you to CardA1 since the button
was copied from the one in CardB1. Make a new card, and enter text into
the field until the field is mostly full. Make sure that there is text
intersecting the bounding box of the button in the other stack. Now
click "This card" in the link-to dialog box, which has stayed visible through
all this.
THE BUG: When the link finishes, and you are back at CardB2, the text from
the field on cardA2 will be showing inside the bounding box of the button. This
is a display bug only, since if you go somewhere else and come back, it isn't
there anymore.
Caveat: I'm not sure I fully understand all the necessary preconditions for
this bug, but I was able to reproduce it twice. The names for the cards don't
matter, they're just for clarity in describing the bug. My best guess is
that some buffer is doing double duty when it shouldn't be, or some attempt
at optimizing redraw time took an unsafe shortcut.
Anyone at Apple who is working on this, please email me if you want further
details. I'll send my actual stacks if you can't reproduce this.
--
Howard A. Landman
{oliveb,hplabs}!intelca!mipos3!cpocd2!howard
howard%cpocd2.intel.com@RELAY.CS.NET
"Get-in-to-tock-ing-hy-per-ma-ni-a"raylau@dasys1.UUCP (Raymond Lau) (12/03/87)
Speaking of bugs in HC 1.0.1...one of Apple's TNs (forgot which) said that
if you set a password, quit out....get back in and then convert the stack
to private (or something like that), the stack will be garbage....
--
Raymond Lau {allegra,philabs,cmcl2}!phri\
Big Electric Cat Public Unix {bellcore,cmcl2}!cucard!dasys1!raylau
New York, NY, USA {sun}!hoptoad/
GEnie:RayLau Delphi:RaymondLau CIS:76174,2617
"Take it and StuffIt."