Keep every line of a multi-line message in chat history

The text log has a message's line breaks in it, but history was read one
line at a time, so every line after the first failed to parse and was
dropped. A line that starts no entry of its own now continues the
message before it, which also recovers what earlier versions wrote.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ts3-client/core/src/main/java/com/ts3client/chatlog/ChatLogStore.java

@@ -175,13 +175,33 @@ public final class ChatLogStore {
         return entries;
     }
 
+    /**
+     * A message is written as it was sent, so one with line breaks spans several lines of the
+     * log: a line that starts no entry of its own continues the message before it.
+     */
     private static List<String> readTextMessages(LogFiles files, ChatLogScope scope) throws IOException {
         if (!Files.isRegularFile(files.txt)) return Collections.emptyList();
         List<String> entries = new ArrayList<>();
+        Matcher message = null;
+        StringBuilder text = new StringBuilder();
         for (String line : Files.readAllLines(files.txt, StandardCharsets.UTF_8)) {
-            String entry = textLineToHtml(line, scope);
+            Matcher m = TEXT_MESSAGE.matcher(line);
-            if (entry != null) entries.add(entry);
+            boolean begin = line.startsWith("*** ");
+            if (!m.matches() && !begin) {
+                if (message != null) text.append('\n').append(line);
+                continue;
             }
+            if (message != null) entries.add(messageLineHtml(message, text, scope));
+            message = null;
+            if (begin) {
+                entries.add(beginLineHtml(line));
+            } else {
+                message = m;
+                text.setLength(0);
+                text.append(m.group(3));
+            }
+        }
+        if (message != null) entries.add(messageLineHtml(message, text, scope));
         return entries;
     }
 
@@ -190,14 +210,12 @@ public final class ChatLogStore {
         return new ArrayList<>(entries.subList(entries.size() - limit, entries.size()));
     }
 
-    private static String textLineToHtml(String line, ChatLogScope scope) {
+    private static String beginLineHtml(String line) {
-        if (line == null || line.isBlank()) return null;
-        if (line.startsWith("*** ")) {
         return "<div class=\"TextMessage_BeginHistory\"><span class=\"Body\">"
                 + BBCode.escape(line) + "</span></div>";
     }
-        Matcher m = TEXT_MESSAGE.matcher(line);
+
-        if (!m.matches()) return null;
+    private static String messageLineHtml(Matcher m, CharSequence text, ChatLogScope scope) {
         String target = switch (scope) {
             case PRIVATE -> "Private";
             case CHANNEL -> "Channel";
@@ -206,7 +224,8 @@ public final class ChatLogStore {
         return "<div class=\"TextMessage_Message Incoming Neutral " + target + "\"><span class=\"Body\">"
                 + "<span class=\"TextMessage_Time\">&lt;" + m.group(1) + "&gt;</span> "
                 + "<span class=\"TextMessage_UserLink\">&quot;" + BBCode.escape(m.group(2)) + "&quot;</span>: "
-                + "<span class=\"TextMessage_Text\">" + BBCode.toHtml(m.group(3)) + "</span></span></div>";
+                + "<span class=\"TextMessage_Text\">" + BBCode.toHtml(text.toString().stripTrailing())
+                + "</span></span></div>";
     }
 
     private static String beginHtml(String kind, LocalDateTime timestamp) {

ts3-client/core/src/test/java/com/ts3client/chatlog/ChatLogStoreTest.java

@@ -68,4 +68,16 @@ class ChatLogStoreTest {
         assertTrue(capped.truncated());
         assertTrue(capped.entries().get(9).contains("filler " + (ChatLogStore.HISTORY_LIMIT - 1)));
     }
+
+    @Test
+    void readsAMessageWithLineBreaksBackWhole() throws Exception {
+        ChatLogStore logs = new ChatLogStore(temp, "+Tyg2JtxE8vRNZp+JiUBnmBh0MY=");
+        logs.appendMessage(ChatLogScope.CHANNEL, false, 5, "uid", "alice", "first line\n\nthird line");
+        logs.appendMessage(ChatLogScope.CHANNEL, false, 5, "uid", "bob", "reply");
+
+        List<String> history = logs.channelHtmlHistory();
+        assertEquals(2, history.size());
+        assertTrue(history.get(0).contains("first line<br><br>third line"), history.get(0));
+        assertTrue(history.get(1).contains("reply"));
+    }
 }