In Magit buffers, or helm-swoop, an unclosed double quote enables the string highlighting for the rest of the buffer (until another quote is found). This is how it looks like:
Because of that, I also lose the green/red highlighting of added/removed lines in Magit. When I disable the font-lock-mode, everything becomes fine (blue text is not blue anymore, +/- lines are colored).
I could add hooks to disable font-lock-mode in those buffers but it is too much trouble to do that for every buffer. Can I somehow find out what causes the screwup in the first place?