QgsDelimitedTextSourceSelect: add a limitation to the number of fields

rouault · rouault · commit fcf6203cb8ae · 2020-05-28T20:42:32.000+02:00
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
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 );
 }
 
@@ -403,6 +404,7 @@ 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;

Original file line number	Diff line number	Diff line change
`@@ -98,6 +98,7 @@ QgsDelimitedTextSourceSelect::QgsDelimitedTextSourceSelect( QWidget *parent, Qt:`
`98`	`98`	`mFileWidget->setDialogTitle( tr( "Choose a Delimited Text File to Open" ) );`
`99`	`99`	`mFileWidget->setFilter( tr( "Text files" ) + QStringLiteral( " (.txt .csv .dat .wkt);;" ) + tr( "All files" ) + QStringLiteral( " (* .)" ) );`
`100`	`100`	`mFileWidget->setSelectedFilter( settings.value( mSettingsKey + QStringLiteral( "/file_filter" ), QString() ).toString() );`
	`101`	`+ mMaxFields = settings.value( mSettingsKey + QStringLiteral( "/max_fields" ), DEFAULT_MAX_FIELDS ).toInt();`
`101`	`102`	`connect( mFileWidget, &QgsFileWidget::fileChanged, this, &QgsDelimitedTextSourceSelect::updateFileName );`
`102`	`103`	`}`
`103`	`104`
`@@ -403,6 +404,7 @@ bool QgsDelimitedTextSourceSelect::loadDelimitedFileDefinition()`
`403`	`404`	`mFile->setUseHeader( cbxUseHeader->isChecked() );`
`404`	`405`	`mFile->setDiscardEmptyFields( cbxSkipEmptyFields->isChecked() );`
`405`	`406`	`mFile->setTrimFields( cbxTrimFields->isChecked() );`
	`407`	`+ mFile->setMaxFields( mMaxFields );`
`406`	`408`	`return mFile->isValid();`
`407`	`409`	`}`
`408`	`410`