In Shell-script mode, indentation after a line continuation seems broken:

aaaaaaaaaaaaaaaaaaaa \
    indents to the correct 4 spaces, but

aaaaaaaaaa aaaaaaaaa \
           indents to the first whitespace in the line

${aaaaaaaaaaa}aaaaa \
              indents to after the closing bracket

( aaaaaaaaa ) && aa \
                     indents to after the line continuation

This seems to be very underisable, and there should at least be an option
of getting back the old behaviour of a fixed indent.