106822 - Do not assume "getAttribute()" method will return an empty string

Status: VERIFIED FIXED

(SeaMonkey :: Composer, defect)

Description

[Charles Manske]

Recent string code changes result in fundamental change in the "getAttribute()"
method. It now returns null instead of an empty string. This caused bug 106733,
and I have found 2 other instances of the pattern:
   if (foo.getAttribute("bar").toLowerCase() == ...
in Composer code, that will cause JS exceptions. E.g., the HLine properties dialog
no longer works because of this kind of error.

Comment 1

[Charles Manske]

Attachment: Fix for first pass at detecting problems because of null strings

Comment 2

[Charles Manske]

There may be other more indirect instances of problems caused by null strings,
but I suggest we checkin fixes as we find such problems ASAP, but keep the bug 
open for awhile to monitor potential problems.

Comment 3

[Charles Manske]

Attachment: More fixes to adjust to different return value when attribute doesn't exist

Comment 4

[Charles Manske]

patch on 10/26/01 includes fix to editor.js for bug 106733, which is the same 
cause.
CC'ing JST, who should do the SR for this.

Comment 5

[sujay]

named anchor dialog is also messed up on the trunk.

Comment 6

[Charles Manske]

Note: 10/26/01 09:26 patch eliminates the '.trimString()' extension to the 
string class. It is now risky to use since the string can be null.
We already had a standard "TrimString(inString)" method and that 
always returns an empty string instead of null, so that's what we should use from
now on.

Comment 7

[Charles Manske]

Attachment: Minor tweak on last patch: Adjust for null return instead of empty string from getAttribute()

Comment 8

[Charles Manske]

With the patch from 10/26/01 10:17, all of Composer's dialogs and toolbars seem
to work now, except for the "New" button problem in bug 106728, which I'm 
investigating separately.

Comment 9

[kinmoz]

Comment on attachment 55260 [details] [diff] [review]
Minor tweak on last patch: Adjust for null return instead of empty string from getAttribute()

sr=[e-mail]

Thanks for doing the sweep.

Comment 10

[Charles Manske]

To help reviewers, here's the TrimString method:
// Remove whitespace from both ends of a string
function TrimString(string)
{
  if (!string) return "";
  return string.replace(/(^\s+)|(\s+$)/g, '')
}

Comment 11

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 55260 [details] [diff] [review]
Minor tweak on last patch: Adjust for null return instead of empty string from getAttribute()

Looks good. r=bzbarsky

Comment 12

[Charles Manske]

checked in

Comment 13

[Charles Manske]

Rechecked all the "getAttribute" calls to verify