I originally reported this here: https://bugs.gentoo.org/show_bug.cgi?id=486802

1. make these two files:
a:
<a a="a" b="b">
b:
<a b="b" a="a">

2. open them both in meld. (meld a b)

3. in the right editor (editing the file "b"), highlight the text, `b="b"`

4. cut the text (ctrl+x or right click -> cut)

5. press backspace

6. click right before the ">"

7. enter one space

8. paste the text (ctrl+v or right click -> paste)

Your final result of "b" should looks like this (same as "a"):  <a a="a" b="b">

Actual behavior:

The pasted text is highlighted in read, although a banner appears saying the files are identical. See attached image.

Expected behavior:

Banner saying files are identical appears and there is no highlighting.

tested on 1.7.0 and 1.8.1