[wp-trac] [WordPress Trac] #43012: Cannot Update Post in Firefox Due to Editor and TinyMCE JavaScript TypeErrors

[WordPress Trac]

#43012: Cannot Update Post in Firefox Due to Editor and TinyMCE JavaScript
TypeErrors
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 Reporter:  johnschulz    |      Owner:
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Editor        |    Version:  4.9.1
 Severity:  normal        |   Keywords:
  Focuses:                |
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 I'm using Firefox 58, on OSX 10.12.6 (Sierra). On a WP 4.9.1 site, I'm
 experiencing issues making changes and saving a post due to an apparent WP
 Editor/TinyMCE/Firefox bug.  When I make changes to a post and then
 attempt to Update the post, I get the following error in the console:
 {{{TypeError: a is null}}} from {{{wp-admin/js/editor.min.js}}}.

 The code seems to revolve around this piece of code: {{{var
 b=a.getWin(),c=b.getSelection();if(!(c.rangeCount<=0)){var
 d="SELRES_"+Math.random()}}}.  If I add a null check for the c variable
 before trying to check the rangeCount like this
 {{{if(!(!c||c.rangeCount<=0))}}} I don't get errors from editor.min.js.
 However, I then get a similar error from {{{wp-
 includes/js/tinymce/tinymce.min.js}}}.

 The following code, similarly, seems to be the issue:
 {{{d=c.rangeCount>0}}}. And similarly a null check clears that TypeError
 as well: {{{d=(!c||c.rangeCount>0)}}}.

 With both of those changes, the changes to the post can be Updated
 successfully.

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Ticket URL: <https://core.trac.wordpress.org/ticket/43012>
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