import-checker: use testparseutil.embedded() to centralize detection logic
This patch fixes issues of embedded() in import-checker.py below, too.
- overlook (or mis-detect) the end of inline script in doctest style
- overlook inline script in doctest style at the end of file
(and ignore invalid un-closed heredoc at the end of file, too)
- overlook code fragment in styles below
- "python <<EOF" (heredoc should be "cat > file <<EOF" style)
- "cat > foobar.py << ANYLIMIT" (limit mark should be "EOF")
- "cat << EOF > foobar.py" (filename should be placed before limit mark)
- "cat >> foobar.py << EOF" (appending is ignored)
$ hg init
$ touch a
$ unset HGUSER
$ echo "[ui]" >> .hg/hgrc
$ echo "username= foo" >> .hg/hgrc
$ echo " bar1" >> .hg/hgrc
$ hg ci -Am m
adding a
abort: username 'foo\nbar1' contains a newline
[255]
$ rm .hg/hgrc
$ HGUSER=`(echo foo; echo bar2)` hg ci -Am m
adding a
abort: username 'foo\nbar2' contains a newline
[255]
$ hg ci -Am m -u "`(echo foo; echo bar3)`"
adding a
transaction abort!
rollback completed
abort: username 'foo\nbar3' contains a newline!
[255]