File 0002-Fix-crash-Make-sure-the-display-cursor-is-valid-afte.patch of Package ktexteditor.7413

From 98c449878f59ea99772e20c19ebff7e01b84068c Mon Sep 17 00:00:00 2001
From: Dominik Haumann <dhaumann@kde.org>
Date: Thu, 8 Sep 2016 15:32:39 +0200
Subject: [PATCH 2/3] Fix crash: Make sure the display cursor is valid after
 text folding

This bug existed at least since KDE 4.3 (2009), took a long time to track it down.

FIXED-IN: KDE Frameworks 5.27
BUG: 367466
Differential-Revision: https://phabricator.kde.org/D2709
(cherry picked from commit 09a1e864d54735ebcab6bf31198fdef969b92a67)
---
 autotests/src/katefoldingtest.cpp | 38 ++++++++++++++++++++++++++++++++++++++
 autotests/src/katefoldingtest.h   |  1 +
 src/view/kateviewinternal.cpp     |  7 +++++++
 3 files changed, 46 insertions(+)

diff --git a/autotests/src/katefoldingtest.cpp b/autotests/src/katefoldingtest.cpp
index a2526d5..79f88fe 100644
--- a/autotests/src/katefoldingtest.cpp
+++ b/autotests/src/katefoldingtest.cpp
@@ -110,3 +110,41 @@ void KateFoldingTest::testBug295632()
     QString line = doc.line(0);
     QCOMPARE(line, QString("oooox----------"));
 }
+
+// This testcase tests the follwing:
+// - the cursor is first set into the word 'hello'
+// - then lines 0-3 are folded.
+// - the real text cursor is still in the word 'hello'
+// - the important issue is: The display cursor must be in the visible line range
+// --> if this test passes, KateViewInternal's m_displayCursor is properly adapted.
+void KateFoldingTest::testCrash367466()
+{
+    KTextEditor::DocumentPrivate doc;
+    QString text = "fold begin\n"
+                   "\n"
+                   "\n"
+                   "fold end\n"
+                   "hello\n"
+                   "world\n";
+    doc.setText(text);
+
+    // view must be visible...
+    KTextEditor::ViewPrivate *view = static_cast<KTextEditor::ViewPrivate *>(doc.createView(0));
+    view->show();
+    view->resize(400, 300);
+    view->setCursorPosition(KTextEditor::Cursor(5, 2));
+    QCOMPARE(view->cursorPosition(), KTextEditor::Cursor(5, 2));
+    qint64 foldId = view->textFolding().newFoldingRange(KTextEditor::Range(0, 0, 3, 8));
+
+    view->textFolding().foldRange(foldId);
+    QVERIFY(view->textFolding().isLineVisible(0));
+    QVERIFY(!view->textFolding().isLineVisible(1));
+    QVERIFY(!view->textFolding().isLineVisible(2));
+    QVERIFY(!view->textFolding().isLineVisible(3));
+    QVERIFY(view->textFolding().isLineVisible(4));
+    QVERIFY(view->textFolding().isLineVisible(5));
+
+    QCOMPARE(view->cursorPosition(), KTextEditor::Cursor(5, 2));
+    view->up();
+    QCOMPARE(view->cursorPosition(), KTextEditor::Cursor(4, 2));
+}
diff --git a/autotests/src/katefoldingtest.h b/autotests/src/katefoldingtest.h
index 0cb8197..9482678 100644
--- a/autotests/src/katefoldingtest.h
+++ b/autotests/src/katefoldingtest.h
@@ -33,6 +33,7 @@ public Q_SLOTS:
 private Q_SLOTS:
     void testCrash311866();
     void testBug295632();
+    void testCrash367466();
 };
 
 #endif // KATE_FOLDING_TEST_H
diff --git a/src/view/kateviewinternal.cpp b/src/view/kateviewinternal.cpp
index 8f9d4db..13d031e 100644
--- a/src/view/kateviewinternal.cpp
+++ b/src/view/kateviewinternal.cpp
@@ -707,6 +707,10 @@ void KateViewInternal::slotRegionVisibilityChanged()
 
         // set cursor to start of folding region
         updateCursor(foldingRange.start(), true);
+    } else {
+        // force an update of the cursor, since otherwise the m_displayCursor
+        // line may be below the total amount of visible lines.
+        updateCursor(m_cursor, true);
     }
 
     updateView();
@@ -1514,6 +1518,9 @@ void KateViewInternal::cursorUp(bool sel)
         return;
     }
 
+    // assert that the display cursor is in visible lines
+    Q_ASSERT(m_displayCursor.line() < m_view->textFolding().visibleLines());
+
     /**
      * move cursor to start of line, if we are at first line!
      */
-- 
2.10.0