Bug 701669 - Bad assumption in prefer-plain module

For messages with a base MIME type of multipart/alternative, we were
hiding text/plain subparts based on the number of alternate subparts.

This assumption of course broke on a message with the following body
structure and a Plain Text Mode preference of "Show HTML if present":

    multipart/alternative
        text/plain
        text/plain

Instead, note when we've actually seen a text/html subpart and use that
to decide whether to hide the text/plain parts.

(cherry picked from commit 35582bf4e29cc4aadf779d76096ef6dd47a7be1a)

0 files changed, 0 insertions, 0 deletions