TGraph axis limits not set properly

[IFTClerk]

I noticed that some TGraph canvases are failing to draw properly when I updated my JSROOT version. The x axis limits are not automatically set to the correct range. If I do "unzoom" on the frame it fixes the drawing.

Drawn:

Expected:

I did a git bisect and it looks like the behaviour was changed in commit 435c3aea629f5912830eeffe57c8935638b67804. The reason seems to be that createHistogram() used to always be called with set_x and set_y as True, which is no longer the case.

It seems like when the TGraph object is loaded, it creates the fHistogram object, but it doesn't set the correct axis limits. Since the object exists, jsroot does not try to create a new histogram, or set axis limits.

When I load the object in ROOT, the TH1F associated with the TGraph has the correct limits.

[linev]

Can you attach ROOT file with such TGraph object?

And sorry for delay - I was in long vacations

[IFTClerk]

No worries. Here's the file on cernbox: https://cernbox.cern.ch/s/vWxJSA4XpjUIvws
Let me know if you have any issues accessing it. The graphs with the bug are the cToFavg* ones.

[linev]

Idea of JSROOT is to avoid creation of histogram every time TGraph is painted - this is how plain ROOT works.
Therefore one tries to check histogram ranges.

Now I create PR #387 which should better works for your case.
I also will backport it to 7.10 branch

[linev]

Fix released with 7.10.2 version