[sdk/kdiff3/1.13] src: Protect against early start resize signals from Qt.

Git commit 656a1d066cd5f5bb48035dfa67cd578882ee20a7 by Michael Reeves.
Committed on 16/07/2026 at 00:53.
Pushed by mreeves into branch '1.13'.

Protect against early start resize signals from Qt.

M  +1    -0    src/SourceData.cpp
M  +14   -9    src/difftextwindow.cpp

https://invent.kde.org/sdk/kdiff3/-/commit/656a1d066cd5f5bb48035dfa67cd578882ee20a7

diff --git a/src/SourceData.cpp b/src/SourceData.cpp
index c48cdbef..b98a7e81 100644
--- a/src/SourceData.cpp
+++ b/src/SourceData.cpp
@@ -175,6 +175,7 @@ const std::shared_ptr<LineDataVector>& SourceData::getLineDataForDisplay() const
 
 LineType SourceData::lineCount() const
 {
+    assert(m_normalData.m_pBuf != nullptr);
     return SafeInt<LineType>(m_normalData.lineCount());
 }
 
diff --git a/src/difftextwindow.cpp b/src/difftextwindow.cpp
index 18990894..afe0f458 100644
--- a/src/difftextwindow.cpp
+++ b/src/difftextwindow.cpp
@@ -296,6 +296,7 @@ const Diff3LineVector* DiffTextWindow::getDiff3LineVector() const
 
 qint32 DiffTextWindow::getLineNumberWidth() const
 {
+    assert(d->mSourceData != nullptr);
     return std::floor(std::log10(std::max(d->mSourceData->lineCount(), 1))) + 1;
 }
 
@@ -1393,16 +1394,20 @@ QString DiffTextWindowData::getLineString(const LineType line) const
 
 void DiffTextWindow::resizeEvent(QResizeEvent* e)
 {
-    QSize newSize = e->size();
-    QFontMetrics fm = fontMetrics();
-    LineType visibleLines = newSize.height() / fm.lineSpacing() - 2;
-    //TODO: Fix after line number area is converted to a QWidget.
-    qint32 visibleColumns = newSize.width() / fm.horizontalAdvance(u'0') - d->leftInfoWidth();
+    //Qt sends resize events before init under certain conditions. No good way to avoid this so just tell Qt to handle it.
+    if(d->mSourceData != nullptr)
+    {
+        QSize newSize = e->size();
+        QFontMetrics fm = fontMetrics();
+        LineType visibleLines = newSize.height() / fm.lineSpacing() - 2;
+        //TODO: Fix after line number area is converted to a QWidget.
+        qint32 visibleColumns = newSize.width() / fm.horizontalAdvance(u'0') - d->leftInfoWidth();
 
-    if(e->size().height() != e->oldSize().height())
-        Q_EMIT resizeHeightChangedSignal(visibleLines);
-    if(e->size().width() != e->oldSize().width())
-        Q_EMIT resizeWidthChangedSignal(visibleColumns);
+        if(e->size().height() != e->oldSize().height())
+            Q_EMIT resizeHeightChangedSignal(visibleLines);
+        if(e->size().width() != e->oldSize().width())
+            Q_EMIT resizeWidthChangedSignal(visibleColumns);
+    }
     QWidget::resizeEvent(e);
 }