QgsDelimitedTextSourceSelect: add a limitation to the number of fields

Set to 10000 by default. Can be overriden through settings. This is only for the preview in the source select dialog. (Attribute table performs badly for much less columns) Related to #36392 (cherry picked from commit fcf6203)
qgis · Jul 21, 2020 · 3c96070 · 3c96070
1 parent c6b2ee0
commit 3c96070
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diff --git a/src/providers/delimitedtext/qgsdelimitedtextsourceselect.cpp b/src/providers/delimitedtext/qgsdelimitedtextsourceselect.cpp
@@ -98,6 +98,7 @@ QgsDelimitedTextSourceSelect::QgsDelimitedTextSourceSelect( QWidget *parent, Qt:
   mFileWidget->setDialogTitle( tr( "Choose a Delimited Text File to Open" ) );
   mFileWidget->setFilter( tr( "Text files" ) + QStringLiteral( " (*.txt *.csv *.dat *.wkt);;" ) + tr( "All files" ) + QStringLiteral( " (* *.*)" ) );
   mFileWidget->setSelectedFilter( settings.value( mSettingsKey + QStringLiteral( "/file_filter" ), QString() ).toString() );
+  mMaxFields = settings.value( mSettingsKey + QStringLiteral( "/max_fields" ), DEFAULT_MAX_FIELDS ).toInt();
   connect( mFileWidget, &QgsFileWidget::fileChanged, this, &QgsDelimitedTextSourceSelect::updateFileName );
 }
 
@@ -401,6 +402,7 @@ bool QgsDelimitedTextSourceSelect::loadDelimitedFileDefinition()
   mFile->setUseHeader( cbxUseHeader->isChecked() );
   mFile->setDiscardEmptyFields( cbxSkipEmptyFields->isChecked() );
   mFile->setTrimFields( cbxTrimFields->isChecked() );
+  mFile->setMaxFields( mMaxFields );
   return mFile->isValid();
 }
 

diff --git a/src/providers/delimitedtext/qgsdelimitedtextsourceselect.h b/src/providers/delimitedtext/qgsdelimitedtextsourceselect.h
@@ -50,6 +50,8 @@ class QgsDelimitedTextSourceSelect : public QgsAbstractDataSourceWidget, private
     std::unique_ptr<QgsDelimitedTextFile> mFile;
     int mExampleRowCount = 20;
     int mBadRowCount = 0;
+    static constexpr int DEFAULT_MAX_FIELDS = 10000;
+    int mMaxFields = DEFAULT_MAX_FIELDS; // to avoid Denial Of Service (at least in source select). Configurable through /max_fields settings sub-key.
     QString mSettingsKey;
     QString mLastFileType;
     QButtonGroup *bgFileFormat = nullptr;