TAB leaves point in the wrong place

[Barry Warsaw]

r1225

import tarfile

src = tarfile.open('src.tgz', 'r:gz')
dst = tarfile.open('dst.tgz', 'w:gz')

for name in src.getnames():
    print('name:', name)
    info = src.getmember(name)
    fp = src.extractfile(name)
    dst.addfile(info, fp)

src.close()
dst.close()

Put point at the end of the `dst.addfile` line and hit return. Point is properly left on the next line right under the first 'd'. Now hit TAB. Point is correctly left at the beginning of the line. Hit TAB one more time.

Now, while 4 spaces have been added to the beginning of the line, point is left at the beginning of the line instead of at the end of the just inserted whitespace. Point should be at column 4.