This bug was initially created as a copy of Bug #2010398

I am copying this bug because:

Sample reproducer:

<< rhel5 and any bash version go to $HOME or directory not in $PATH >>

$ cd
$ cat > a <<EOF
echo foo
EOF
$ source a
foo

<< rhel6 and newer with ksh after creating the file to be sourced >>
$ source a
ksh: .: a: cannot open [No such file or directory]

but bash works, and is documented to do so.

The code is basically identical from rhel5 to rhel7, major difference is:

https://github.com/ksh93/ksh/blame/master/src/cmd/ksh93/sh/path.c#L403

that is, newer ksh has:

if(pp->flags&PATH_SKIP)
return(ppnext);

and older ksh has:

if(pp->flags&PATH_SKIP)
continue;

there is nothing useful in git blame or changelog that I could see.

What was noticed is that on older ksh when traversing pp
(shp->pathlist), due to the 'do {} while' in path_opentype, it eventually
calls sh_open with just the file name, not a prefix, while on newer ksh, it
calls sh_open twice with the last component in the $PATH.

This makes ksh different from bash, and cause the source command to require
'.' in $PATH to be able to source files in the current directory.