M11, Build ID: 1999111520, Win98 &RH Linux 6.1 When background image is larger than window results to wierd effect during scrolling. On Linux everything is black but on Win98 screen pixels are taken from memory so it's very colourful. Ivo Särak.

* Overview: The display problem reported here can create a serious usability problem with a large, slow-loading BODY BACKGROUND image: black text over the as-yet-unloaded portions of the background cannot be read. * Steps to Reproduce: 0. This bug is easiest to reproduce with a slow modem link; if the background loads too quickly it may be difficult or impossible to reproduce - so use a dialup connection if possible, and load it down with a concurrent ftp download for maximum effect. 1. Adjust the browser window to 700-750 pixels tall. 2. View the 12/07 testcase above and click on the "Document with 2k by 2k background" link. 3. Scroll down to the bottom of the document as soon as possible, and then up by one [PgUp]. * Actual Results: A. Within a second or two after the background begins loading, the entire area that it will cover but has not yet covered is changed to black - black text on top of that is unreadable. Selecting this text makes it no more readable: the black background is inverted too. B. In step 3, it can be seen that the second tile (vertically) of the background loads at the same time as the first tile; the as-yet-unloaded part of the first tile will still be black while the first part of the second tile is displayed. Where "a" is any natural number from zero up, "n" is the height of the background in px, and "x" is the number of rows of pixels displayed at a particular time, the text above the regions (a)*(n) to (a)*(n)+(x) can be read, and the text above the regions (a)*(n)+x+1 to (a+1)*(n)-1 cannot be read, unless it is a colour that contrasts sufficiently with black. * Expected Result: The background of any area where a background image will be displayed will remain whatever it was before the background image began to load until the background image actually appears in that area; no difficulties reading text while the background image loads. * Tested with: 1999-12-07-08-M12 nightly binary on Windows NT 4.0sp3 1999-12-05-12-M12 nightly binary on Windows NT 4.0sp3 * Additional Information: This problem shows to a lesser extent with some of the other extreme sized background testcases linked from the attachment; some of these also create performance problems in scrolling. This may be intentional during development for some good reason; if that is the case, this bug report should probably get a late milestone assigned to make sure that the code that turns the background's area black is turned off or removed prior to shipping. Changing component to "Layout" as a first try.

This looks like a DUP of bug #1248. The bug is that we render parts of an image that haven't yet loaded and so we display junk there Pam, when is this bug going to get fixed? It's been around for ever... *** This bug has been marked as a duplicate of 1248 ***

Troy: Its been low on the priority list. -pn

Marking Verified as a dup.