Kristoffer Balintona <krisbalintona@gmail.com> writes:

Hello,

I am writing to report a bug in rainbow-mode. The bug is simple: when
enabling rainbow-mode in help-mode buffers, function argument names are
not fontified as they should be.

Expected behavior:
Function arguments in help-mode buffers should have the
help-argument-name face applied to them (when help-display-function-type
is non-nil, I think).

Actual behavior:
With rainbow-mode enabled, this is not the case. Instead, argument names
have no face. Disabling rainbow-mode and reverting the buffer
(revert-buffer) returns the expected fontification.

I'm not rainbow-mode author or maintainer, but this is a font-lock
downside (which rainbow-mode uses), font-lock overrides any
text-property (faces) made in the buffer.

Also this is the same problem with all minor modes that uses font-lock.