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Input box has cursor and character display errors when displaying non-printable character using Javascript.




10 years ago
9 years ago


(Reporter: Chad Weber, Unassigned)


3.0 Branch
Windows XP

Firefox Tracking Flags

(Not tracked)





10 years ago
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20080404 Firefox/
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20080404 Firefox/

When an input box displays a non-printable character, adding a character to the end of the line causes the non-printable character to be displayed as a rectangle, the cursor to appear halfway through the newly-typed character and only show the first half of that character. If the printable character is removed, the non-printable character's rectangle will disappear and will reappear if another character is added to the end of the line.

The corruption on the specific character is corrected when that area of the screen is refreshed (for example: by scrolling, moving the cursor onto the character, or by typing another character). This is why it only causes issues with a newly-typed character at the end of the line.

This also causes character corruption when deleting characters from the same line.

Also, using Ctrl+Home, when at the end of the line, to select the line will not select the non-printable character and neither can the mouse, but it can be selected by using the Shift and arrow key combination.

Reproducible: Always

Steps to Reproduce:
1. Go to http://www.blooberry.com/indexdot/html/topics/urlencoding.htm
2. Scroll to the "URL encoding converter" section and click the "<- Convert ->" button.
3. Enter %08 into the input box and click the button again.
4. Type several wide characters (they show the corruption better) into the input box to view the cursor error and character corruption.
5. Delete a few of the printable characters, from the end, one at a time using backspace to view the character corruption.
6. Attempt to select the non-printable character using the mouse and Ctrl+Home when at the end of the line to see that the non-printable character is not selected. Then select it using the Shift and arrow keys to see that it can be selected.
Actual Results:  
There were cursor errors, character corruption, and selection issues as described in the Details section.

Expected Results:  
The cursor should have behaved as a cursor is normally expected to behave. Characters should have been displayed properly, without the corruption.

Non-printable characters should behave however they are supposed to behave if this is not the desired behavior.


9 years ago
Product: Firefox → Toolkit
WFM on FF3.1 trunk, OSX. Can you still reproduce this in a current Firefox release?

Comment 2

9 years ago
Firefox 3 corrects the problem, by using the square character code symbols.
Last Resolved: 9 years ago
Component: Form Manager → General
Product: Toolkit → Firefox
Resolution: --- → FIXED
Version: unspecified → 3.0 Branch
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