Opening two or more tabs in quick succession corrupts location of viewport

[jogoodma]

FlyBase has had a dozen reports from users who are having trouble with following GBrowse links that point to specific location points. For example,

http://flybase.org/cgi-bin/gbrowse2/dmel/?ref=2R;start=14479585;stop=14483603;
http://flybase.org/cgi-bin/gbrowse2/dmel/?ref=2L;start=15260611;stop=15264625;

After opening links such as these in their own tab and in quick succession
so that Tab 1 is still loading when Tab 2 initiates a request, the
view shown in Tab 1 is corrupted. Tab 1 shows the correct URL in the
browser address bar, but the region shown corresponds to the region
for Tab 2. The tab title and the GBrowse region title also display
the incorrect region.

e.g.
' D. melanogaster: 4.015 kbp from 2L:15,260,611..15,264,625

instead of

' D. melanogaster: 4.019 kbp from 2R:14,479,585..14,483,603

Reloading Tab 1 corrects the corrupted view. If you click each link
after waiting for the tab to load it does not exhibit this behavior.

I've replicated this on the WormBase GBrowse 2.x server using the
links below, so I'm fairly certain that this is a general GBrowse 2 bug and not specific to the
FlyBase installation.

http://www.wormbase.org/tools/genome/gbrowse/c_elegans_PRJNA13758/?ref=III&start=9050076..9061680

http://www.wormbase.org/tools/genome/gbrowse/c_elegans_PRJNA13758/?ref=III&start=8060076..8071680

[nathanweeks]

Hi Josh,

I verified this issue occurs with the SoyBase GBrowse:

http://soybase.org/gb2/gbrowse/gmax2.0/?ref=Gm02;start=15260611;stop=15264625
http://soybase.org/gb2/gbrowse/gmax2.0/?ref=Gm01;start=14479585;stop=14483603

When the URLs were opened in that order, both browser tabs had the second URL.

We're using the "file" session driver; e.g., our GBrowse.conf contains:

session driver    = driver:file;serializer:default

There were two cgi_sessions files created in the sessions directory:

$ ls -lt
...
-rw-r-----  1 www  wheel   5333 Apr 28 16:12 cgisess_73e6ba0ca07e619d994e08283b7c9c73
-rw-r-----  1 www  wheel   5286 Apr 28 16:12 cgisess_d05b4ab3bf009cefba927c0d91314b76
...

The more recent file (cgisess_73*) contained:

'source' => 'gmax2.0','start' => 14475567,'stop' => 14487621

while the older file contained:

'source' => 'gmax2.0','start' => 15256597,'stop' => 15268639

However, looking at both tabs in my browser, the value of the gbrowse_sess cookie was "73e6ba0ca07e619d994e08283b7c9c73".

There seems to be some sort of cookie-related race condition going, though I'm not knowledgeable in this area, and don't know how it could be fixed.