[imp] Reply-quoted paragraphs from HTML-only messages have spurious indentation

[Michael]

Hi

When an HTML message _without_ a plain text alternative part is quoted
for reply in IMP 4.1, two extra spaces are inserted between the
chevron and the first word of every proper paragraph ('/<p[^>]*> ?/i'
=> "\n\n  ").  The result is an odd-looking first-line-only indent for
each quoted paragraph, no matter whether the reply is in plain text or
HTML format.

This is inconsistent: it does not occur with <br>-style linebreak
"paragraphs", with HTML messages that include plain text alternative
parts, or with plain text-only messages, as shown below.  Please note
the extra spaces in the last example.

      Plain text-only original reply-quoting:
      > This paragraph
      > is quoted.

      HTML with plain text alternative original reply-quoting:
      > This paragraph
      > is quoted.

      HTML-only original reply-quoting:
      >   This paragraph
      > is quoted.

I am told that this is not a bug: that first lines of paragraphs are
always indented and that this is a common layout which cannot be
disabled.

In which email clients is this layout common?  I cannot recall ever
seeing this elsewhere, at least not as a default.  It also runs
contrary to traditional Usenet quoting style.

In my view this behaviour goes against established convention and
misrepresents the original text.  Not only could this cause wrapping
issues, but it can also impair clarity if preceded by a line with one
additional level of indentation: the extra spaces cause the first line
to line up with a different writer's text.

Why does IMP operate in this inconsistent manner?  Is unalterable
insertion of foreign whitespace into quoted text in a subset of cases
truly desirable behaviour?

Thank you
Michael