giv getting stuck on Windows when opening 16 bit tiff files

[simonkolotov]

Steps to reproduce:

1. open a 16-bit tiff file (e.g. the attached tiff file - don't forget to rename it to tiff - github limitation in uploading) in giv
2. zoom in or middle-click drag -> The viewer will get stuck and won't respond

Alternative:

1. open a 16-bit tiff file (see above for the attached file) in giv
2. open the "Adjust Contrast" menu -> The menu wiill get stuck and the draggable handles won't respond
   NB: The menu will work when using the contrast value text boxes and the "Update" button

In both cases, toggling one of the "UI" controls, e.g. View->"SubPixel Coords" or any of those will "release" the stuck application, but it will get stuck again when dragging or zomming in (interestingly, the "Adjust Contrast" will at this point keep working unless you close and reopen a new one - which would be stuck as well).
Thus for every zoom drag or reopening of the adjust contrast you need to toggle the GUI.
NB: Toggling the gui to release the application only works from the mouse commands, the keyboard commands (e.g. v for vertical flip) don't get a response while their mouse-clicked menu counterpart do and release the stuck application

Attached: Sample 16-bit tiff file (in txt extension due to github limitation - just rename to tiff)
N98_0002.txt