Sample HTML:
<p>AA<b>A</b>AA</p>
<p>BB<b>B</b>BB</p>
<p>CC<b>C</b>CC</p>
<p>DD<b>D</b>DD</p>


1. Line (home to end)
	AAAAA
	[BBBBB]
	CCCCC
	DDDDD

	Chrome:		BB<b>B</b>BB
	Firefox:	BB<b>B</b>BB
	Opera:		BB<b>B</b>BB
	IE9:		<p>BB<b>B</b>BB</p>
	IE8:		BB<b>B</b>BB

2. Line + LF (home to end + right)
	AAAAA
	[BBBBB
	]CCCCC
	DDDDD

	Chrome:		<p>BB<b>B</b>BB</p><div><br></div>
	Firefox:	<p>BB<b>B</b>BB<br></p>
	Opera:		BB<b>B</b>BB
	IE9:		<p>BB<b>B</b>BB</p>
	IE8:		<p>BB<b>B</b>BB</p>

3. LF + line (end to home + left)
	AAAAA[
	BBBBB]
	CCCCC
	DDDDD

	Chrome:		<br class="Apple-interchange-newline">BB<b>B</b>BB
	Firefox:	<br><p>BB<b>B</b>BB<br></p>
	Opera:		BB<b>B</b>BB
	IE9:		<p>BB<b>B</b>BB</p>
	IE8:		&nbsp; <p>BB<b>B</b>BB</p>
		In this and in all other cases '&nbsp; ' means /^&nbsp;( |\r\n)?<block/g
		I was able to produce trailing space also for IE9, but that was a rare thing.

4. Partial line + LF (home + right to end + right)
	AAAAA
	B[BBBB
	]CCCCC
	DDDDD

	Chrome:		<p>B<b>B</b>BB</p><div><br></div>
	Firefox:	B<b>B</b>BB<br>
	Opera:		B<b>B</b>BB
	IE9:		B<b>B</b>BB
	IE8:		B<b>B</b>BB

5. LF + Partial line (end + left to home + left)
	AAAAA[
	BBBB]B
	CCCCC
	DDDDD

	Chrome:		<br class="Apple-interchange-newline">BB<b>B</b>B
	Firefox:	<br>BB<b>B</b>B
	Opera:		BB<b>B</b>B
	IE9:		<p>BB<b>B</b>B</p>
	IE8:		&nbsp; <p>BB<b>B</b>B</p>

6. Two partial lines
	A[AAAA
	BBBB]B
	CCCCC
	DDDDD

	Chrome:		<p>A<b>A</b>AA</p><p>BB<b>B</b>B</p>
	Firefox:	A<b>A</b>AA<br>BB<b>B</b>B
	Opera:		<p>A<b>A</b>AA</p><p>BB<b>B</b>B</p>
	IE9:		A<b>A</b>AA<p>BB<b>B</b>B</p>
	IE8:		A<b>A</b>AA <p>BB<b>B</b>B</p>

7. Two lines (home to end + down + end)
	AAAAA
	[BBBBB
	CCCCC]
	DDDDD

	Chrome:		<p>BB<b>B</b>BB</p><p>CC<b>C</b>CC</p>
	Firefox:	<p>BB<b>B</b>BB<br></p><p>CC<b>C</b>CC<br></p>
	Opera:		<p>BB<b>B</b>BB</p><p>CC<b>C</b>CC</p>
	IE9:		<p>BB<b>B</b>BB</p><p>CC<b>C</b>CC</p>
	IE8:		<p>BB<b>B</b>BB</p> <p>CC<b>C</b>CC</p>

8. Partial line 1 (home + right to end)
	AAAAA
	B[BBBB]
	CCCCC
	DDDDD

	Chrome:		B<b>B</b>BB
	Firefox:	B<b>B</b>BB
	Opera:		B<b>B</b>BB
	IE9:		B<b>B</b>BB
	IE8:		B<b>B</b>BB

9. Partial line 2 (end + left to home)
	AAAAA
	[BBBB]B
	CCCCC
	DDDDD

	Chrome:		BB<b>B</b>B
	Firefox:	BB<b>B</b>B
	Opera:		BB<b>B</b>B
	IE9:		BB<b>B</b>B
	IE8:		BB<b>B</b>B


Testing procedure:
1. Select given range.
2. Copy.
3. Open plugins/clipboard/samples/clipboard.html.
4. Paste into empty editable (<p>^</p>).
5. Copy result from the paste event with lowest priority (-1).


IE7:
1. <p>BB<b>B</b>BB</p>
2. <p>BB<b>B</b>BB</p>
3. &nbsp; <p>BB<b>B</b>BB</p>
4. ...