1326375 - loadStartPage of mailWindow.js is better to use try{if(location.href!=uri.spec)location.href=uri.spec;}catch(e) instead of try{location.href!=uri.spec;}catch(e) as done in bug 545955 on ClearMessagePane

Status: NEW

(Thunderbird :: Mail Window Front End, defect)

Description

[WADA:World Anti-bad-Duping Agency]

+++ This bug was initially created as a clone of Bug #1326371 +++

loadStartPage of mailWindow.js is better to use try{if(location.href!=uri.spec)location.href=uri.spec;}catch(e) instead of try{location.href!=uri.spec;}catch(e) as done in bug 545955 on ClearMessagePane.

This bug and bug 1326371 were found during analysis of bug 1083994 for ClearMessagePane which sets new-url of browser(id=messagepane) to about:blank using location.href=about:blank.

Because any location.href=xxx request by chrome code to browser(id=messagepane) currently won't wait for load event of previous request, issue like bug 1326371 may be produced due to contension.
Such contension or double-request(excess unload/load) is better reduced as much as possible by if(location.href!=NewURI) unless "wait for load event of previous request" like one will be implemented.

loadStartPage 
  if (startpage)
  {
    try {
      let uri = Services.uriFixup.createFixupURI(startpage, 0);
      GetMessagePaneFrame().location.href = uri.spec;
    }
    catch (e) {
      Components.utils.reportError(e);
    }
  }
  else
  {

Note: Exception occurs here in bug 1083994, even though pretty simple location.href=about:blank
    GetMessagePaneFrame().location.href = "about:blank";
  }
}