Handle Windows line endings and verify empty code blocks

tools/chatgui/src/message_text.cpp

@@ -1,6 +1,8 @@
 #include "message_text.h"
 #include "messagedelegate.h"
 #include "debug_ui.h"
+#include <algorithm>
+#include <climits>
 #include <QCache>
 #include <QFontDatabase>
 #include <QFontMetricsF>
@@ -13,11 +15,11 @@
 #include <KSyntaxHighlighting/Theme>
 
 bool MessageText::isCode(int position) const {
-    for (const auto& block : code) {
-        if (position < block.start) break;
-        if (position <= block.start + block.length) return true;
-    }
-    return false;
+    auto next = std::upper_bound(code.cbegin(), code.cend(), position,
+                                 [](int offset, const MessageCodeBlock& block) { return offset < block.start; });
+    if (next == code.cbegin()) return false;
+    const auto& block = *--next;
+    return position <= block.start + block.length;
 }
 
 namespace {
@@ -94,7 +96,7 @@ public:
         for (offset = block.start; offset < end;) {
             int newline = message.text.indexOf('\n', offset);
             if (newline < 0 || newline > end) newline = end;
-            state = highlightLine(QStringView(message.text).mid(offset, newline - offset), state);
+            state = highlightLine(message.text.mid(offset, newline - offset), state);
             offset = newline + 1;
         }
     }
@@ -114,7 +116,8 @@ protected:
 
 MessageText parseMessageText(const QString& source) {
     MessageText result;
-    const auto lines = source.split('\n');
+    QString normalized = source; normalized.replace("\r\n", "\n");
+    const auto lines = normalized.split('\n');
     static const QRegularExpression fence(QStringLiteral("^```([A-Za-z0-9_+#.-]{0,32})$"));
     QVector<int> closing(lines.size(), -1);
     int next = -1;