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Bug report

Bug summary

The default name for the save dialog is based upon the window/figure title. This is good as it's the only means by which a user's script can influence the default filename.

If the user's title has spaces in it then they are converted to underscores. This modification is not good as it changes the user's intended name but it may be necessary due to some Apps on some OSs not being able to handle spaces in paths.

The bigger problem is that the user- supplied title is ALWAYS converted to lower-case. This is VERY bad. If a user supplies a title that is valid for the OS they are using then they DO NOT expect it to be modified! In our case we have auto-generated filenames 40 or more chars in length with mixed case and it is impractical for the user to re-type this in every time.

If this is not fixed then it is essential to add a function by which the user can set the default name in some other manner.

Code for reproduction
a)

 fig = plt.gcf()
 fig.canvas.set_window_title("Auto_Generated_Very_Specific_Title_That_Is_Very_Annoying_To_ReType")

plt.plot()

b) Manually adjust plot to suit.
c) Click 'save' button.

Actual outcome

Default filename is:
'auto_generated_very_specific_title_that_is_very_annoying_to_retype'

Expected outcome

'Auto_Generated_Very_Specific_Title_That_Is_Very_Annoying_To_ReType'

Matplotlib version

Latest