fix(compose): put the reply cursor on blank space, not on the quote

quote_position names where the QUOTE goes, so the reply belongs on the
other side of it and the cursor has to follow the reply rather than the
buffer. seedBody() moved the cursor to Start under both positions, which
is correct only for Below: under Above, the shipped default, it landed on
the "On ... wrote:" attribution line, so every reply had to have room made
before it could be typed.

End under Above, Start under Below.

The existing theQuotePositionDecidesWhereTheQuoteLands passed throughout
the defect and still does, because the quote was in the right place all
along; only the cursor was not. The new test asserts the cursor's block is
blank, and that typing lands on the correct side of the quote, so a fix
that freed the cursor by inverting the position would not satisfy it.

Also re-measures item 136 in the backlog, which is not the intermittent
race it was filed as: undoMovesTheMessageBack fails 6 runs in 6 when named
alone and passes in the full suite, on a clean tree, so it depends on the
tests before it.

1 files changed, 9 insertions, 6 deletions

diff --git a/src/composewindow.cpp b/src/composewindow.cpp
index 0445c5d..59eaccc 100644
--- a/src/composewindow.cpp
+++ b/src/composewindow.cpp
@@ -442,19 +442,22 @@ void ComposeWindow::seedBody()
     // tracking "my text" and "the quote" as separate pieces to make a toggle
     // reversible is machinery for a case answered by closing the composer and
     // reopening it.
+    // quote_position names where the QUOTE goes, so the reply goes on the
+    // other side of it, and the cursor follows the reply rather than the
+    // buffer. Start in both cases was wrong for Above: it put the cursor on
+    // the attribution line, so the user had to make room before typing.
     if (m_config.compose().quotePosition
         == ComposeSettings::QuotePosition::Above) {
-        // The quote first, then a blank line for the reply to be typed into.
+        // The quote first, then blank lines for the reply, and the cursor in
+        // them. Two lines rather than one so the reply is separated from the
+        // attribution by a blank line once typing starts.
         m_body->setPlainText(m_context.quotedBody + QStringLiteral("\n\n"));
+        m_body->moveCursor(QTextCursor::End);
     } else {
         m_body->setPlainText(QStringLiteral("\n\n") + m_context.quotedBody);
+        m_body->moveCursor(QTextCursor::Start);
     }
 
-    // The cursor at the very top in both cases: with the quote below, the
-    // blank lines the reply goes into are at the top; with it above, the user
-    // scrolls past what they are answering, which is what quoting above means.
-    m_body->moveCursor(QTextCursor::Start);
-
     // The seeded quote is not an edit the user made, so it must not survive as
     // an undo step: one Ctrl+Z on a fresh composer would otherwise wipe the
     // quote and read as the buffer losing its content.