P: Straighten does not work as expected. (crop will be reset)

I can reproduce it using the following steps on Windows 7:

1. Select a new photo in develop. The photo is on Adobe defaults and has 3:2 aspect
2. Enter crop tool
3. Set rotation angle to -20
4. Drag the lower right corner or the crop rectangle slightly left/upwards
5. Make a small adjustment to the rotation angle ===> The crop rectangle resets to full size!

I can't reproduce this either. It might help to know which operating system you're using for a start.

Try laying out steps like this:

1. Select the Straighten tool in the Crop Options panel and drag a line on the photo. Angle slider is automatically set to -13.58.
2. Grab the bottom right corner of the bounding box and drag up and left.
3. Adjust the Angle slider in the Crop Options panel to -15.62.
4. Crop boundaries revert to full photo. Angle slider is reset to 0.

Or whatever you're seeing. (Or if you're fed up with trying to explain, a video is by far the best way of us understanding what you're seeing. You don't even need screen capture - videoing the screen using your phone would do!)

I don't mean the auto straighten tool. I mean the straighten (rotate by arbitrary angle) from crop menu.

ok:
1. straighten
2. crop
3. straighten -> crop will be removed

In your initial post you call your first step a "straighten".
Now in this "correction" post you call the first step a "rotate".

As my first step that changes something about the image I use the straighten ruler in the crop-tool area.

How are you rotating/straightening without using the ruler in the crop tool? Am I supposed to be dragging the angle slider in the crop-tool or doing something in the lens corrections area?

We've asked for specific instructions and all you can say is I'm not doing something that I'm clearly doing at least in one plausible interpretation of your steps.

It would help to use the actual LR terms for what you're doing...the actual tool names.

If you're using a non-English version of LR then perhaps include screenshots with circles or arrows indicating which tools you're using.

You forget the first step.
1. rotate
2. crop
3. rotate -> crop will be lost

Here are the steps I'm using and CANNOT duplicate the issue.

I am starting with a 5472x3648 raw file from my 7D Mark II in LR 6.0.1 on Win 8.1 with the GPU disabled.

I click on the crop tool and see a crop box surrounding my entire image with the crop-aspect of Original which is 3:2.

I click the ruler icon and drag it at an angle and see that the image box tilts and shrinks to make the dragged line horizontal although the line disappears as it should.

Next I adjust the crop box, either dragging it to a different size or a select a different aspect ratio--say 8.5x11. The crop-box resizes as dragged or one dimension shrinks to adjust to the changed aspect.

Then I select the ruler, again, and click-drag at another angle.

The image rotates so that the dragged line is horizontal but the crop-box remains the size and/or aspect I previously had set it unless it needs to be smaller to fit within the image extent.

At no time does the crop-box reset to the extent of the image nor does the aspect change back to Original merely by my dragging the ruler at an angle.

If you're not using LR 6.0.1/CC 2015.0.1 then maybe Adobe fixed it in the .0.1 version. Check Help / System Info to see what version have.

I cannot duplicate on Mac or Windows - unless there is a step I am missing.

Can either of you provide detailed step-by-step instructions?

I am seeing this issue as well. Extremely frustrating.

I cannot duplicate the behavior you are describing.

Perhaps if you list the steps exactly so that we can follow and try to repeat the behavior you are seeing?