1 files changed, 29 insertions, 0 deletions
diff --git a/src/threadcidmap.h b/src/threadcidmap.h
new file mode 100644
index 0000000..76bd8b9
--- /dev/null
+++ b/src/threadcidmap.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <QHash>
+#include <QList>
+#include <QSet>
+#include <QString>
+
+#include "htmlbuilder.h"
+#include "mimeparser.h"
+
+/// The inline parts of a whole thread, keyed by their namespaced cid.
+struct ThreadCidMap
+{
+    QHash<QString, InlinePart> parts;  ///< For the scheme handler.
+    QSet<QString> allowedCids;         ///< For the interceptor. Same keys.
+};
+
+/// Flattens every message's inline parts into one namespaced map.
+///
+/// Two messages in a thread commonly share a Content-ID (cid:logo@example.org
+/// from the same sender's newsletter template), and the thread renders as one
+/// document, so the raw ids would collide and one message would show another's
+/// image. Keys are "<prefix>!<content-id>".
+///
+/// A cidPrefix containing '!' would break the split that keeps those apart, so
+/// it is sanitized here rather than trusted: Q_ASSERT fires in debug builds but
+/// is compiled out in release, and this map decides which bytes a message can
+/// name. Sanitizing is injective, so two distinct prefixes stay distinct.
+ThreadCidMap buildThreadCidMap(const QList<ThreadRenderItem> &items);