RFR: JDK-8176033: New cygwin grep does not match \r as newline

[Tim Bell]

Erik:

Looks good to me.

Tim

> In our configure code for rewriting cygwin paths reliably, we use this
> construct to find the root of the cygwin installation:
>
> # The cmd output ends with Windows line endings (CR/LF), the grep
> command will strip that away
> cygwin_winpath_root=`cd / ; cmd /c cd | $GREP ".*"`
>
> This used to work fine for a long time, but with the latest version of
> cygwin grep, it no longer removes \r from the string. A more robust
> implementation would be to instead use tr to explicitly remove both \r
> and \n.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8176033
>
> Patch:
>
> diff -r fe8466adaef8 common/autoconf/basics_windows.m4
> --- a/common/autoconf/basics_windows.m4 Fri Feb 24 12:01:32 2017 +0100
> +++ b/common/autoconf/basics_windows.m4 Wed Mar 01 10:50:44 2017 +0100
> @@ -329,8 +329,8 @@
>        AC_MSG_ERROR([Something is wrong with your cygwin installation
> since I cannot find cygpath.exe in your path])
>      fi
>      AC_MSG_CHECKING([cygwin root directory as unix-style path])
> -    # The cmd output ends with Windows line endings (CR/LF), the grep
> command will strip that away
> -    cygwin_winpath_root=`cd / ; cmd /c cd | $GREP ".*"`
> +    # The cmd output ends with Windows line endings (CR/LF)
> +    cygwin_winpath_root=`cd / ; cmd /c cd | $TR -d '\r\n'`
>      # Force cygpath to report the proper root by including a trailing
> space, and then stripping it off again.
>      CYGWIN_ROOT_PATH=`$CYGPATH -u "$cygwin_winpath_root " | $CUT -f 1
> -d " "`
>      AC_MSG_RESULT([$CYGWIN_ROOT_PATH])