fix(compose): a resumed draft does not re-seed on a From: change

A resumed draft kept m_signatureChosen false, so a From: change re-seeded
the signature and rewrote what the user had saved, inserting the new
account's where the saved block no longer matched a known file. The draft is
the user's deliberate prior state and must not follow a From: change, so the
draft branch marks it chosen.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/composewindow.cpp b/src/composewindow.cpp
index 94a3f46..d781e52 100644
--- a/src/composewindow.cpp
+++ b/src/composewindow.cpp
@@ -792,6 +792,11 @@ void ComposeWindow::seedSignature()
     // verbatim. Seeding again would append a second one.
     if (m_context.kind == ComposeContext::Kind::Draft) {
         none->setChecked(true);
+        // The draft IS the user's choice: its signature is deliberate prior
+        // state, so a From: change must not follow the new account and
+        // rewrite what was saved. Marking it chosen keeps the same invariant
+        // the switch actions set, without ever having run the switch.
+        m_signatureChosen = true;
         return;
     }