RFR: 8268083: JDK-8267706 breaks bin/idea.sh on a Mac

[Erik Joelsson]

On Fri, 4 Jun 2021 21:23:27 GMT, Nikita Gubarkov <github.com+9004656+YaaZ at openjdk.org> wrote:

> I got rid of `realpath` usage as discussed in https://github.com/openjdk/jdk/pull/4190 and used `RelativePath` macro instead, however there were quite a few problems with this macro, here's the example:
> 
> $(call RelativePath,/foo/bar,/foo/bar/baz) -> "    ..//foo/bar"
> $(call RelativePath,/foo/bar/baz/,/foo/bar/baz) -> SEGFAULT
> $(call RelativePath,/foo/bar/baz/banan,/foo/bar/) -> "    ./baz/banan"
> $(call RelativePath,/foo/bar/baz,/foo/bar/banan) -> "    ../baz"
> 
> As you can see, 1st case is just plain wrong, 2nd crashes make because of infinite loop, 3rd can be simplified and all of them have leading whitespaces
> First commit in this PR fixes all these issues and adds corresponding test cases and second commit replaces usage of `realpath` in idea.sh with `RelativePath` macro in idea.gmk and fixes problems, when paths are incorrectly treated by IDEA

Nice work, this looks great! Thank you for improving the RelativePath macro. Since this is touching some very core and sensitive build functionality, I'm going to run it through all our internal builds just to be safe.

-------------

PR: https://git.openjdk.java.net/jdk/pull/4369