From 4dcedb8ca4ae0c9c533997074098297abbfcf1c3 Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@qt.io>
Date: Tue, 8 Jun 2021 16:49:53 +0200
Subject: Avoid overflow in text layout

Fixes oss-fuzz issue 34597.

Fixes: QTBUG-94197
Change-Id: Icabcd5a87b809b6a5ae0f1a696ec3b5dd906886b
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit e473d96e65e7cf3190c6c16acace6359964d0bee)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp')

diff --git a/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp b/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
index 099ccab51c..4b8ba98d04 100644
--- a/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
+++ b/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
@@ -1910,6 +1910,20 @@ void tst_QTextLayout::longText()
         QFontMetricsF fm(layout.font());
         QVERIFY(layout.maximumWidth() - fm.horizontalAdvance(' ') <= QFIXED_MAX);
     }
+
+    {
+        QTextLayout layout(QString("AAAAAAAA").repeated(200000));
+        layout.setCacheEnabled(true);
+        layout.beginLayout();
+        forever {
+            QTextLine line = layout.createLine();
+            if (!line.isValid())
+                break;
+        }
+        layout.endLayout();
+        QFontMetricsF fm(layout.font());
+        QVERIFY(layout.maximumWidth() - fm.horizontalAdvance('A') <= QFIXED_MAX);
+    }
 }
 
 void tst_QTextLayout::widthOfTabs()
-- 
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