Fix crash in footprint editor when SMD pad diameter is zero. (fixes lp:1378917)

pcbnew/dialogs/dialog_pad_properties.cpp

@@ -151,6 +151,7 @@ private:
     void PadPropertiesAccept( wxCommandEvent& event );
 };
 
+
 void PCB_BASE_FRAME::InstallPadOptionsFrame( D_PAD* aPad )
 {
     DIALOG_PAD_PROPERTIES dlg( this, aPad );
@@ -247,12 +248,39 @@ void DIALOG_PAD_PROPERTIES::OnPaintShowPanel( wxPaintEvent& event )
     // Calculate a suitable scale to fit the available draw area
     int dim = m_dummyPad->GetSize().x + std::abs( m_dummyPad->GetDelta().y );
 
+    // Invalid x size. User could enter zero, or have deleted all text prior to
+    // entering a new value; this is also treated as zero. If dim is left at
+    // zero, the drawing scale is zero and we get a crash.
+    if( dim == 0 )
+    {
+        // If drill size has been set, use that. Otherwise default to 1mm.
+        dim = m_dummyPad->GetDrillSize().x;
+        if( dim == 0 )
+            dim = 1000000;
+    }
+
     if( m_dummyPad->GetLocalClearance() > 0 )
         dim += m_dummyPad->GetLocalClearance() * 2;
 
     double scale = (double) dc_size.x / dim;
 
-    dim = m_dummyPad->GetSize().y + std::abs( m_dummyPad->GetDelta().x);
+    // If the pad is a circle, use the x size here instead.
+    int ysize;
+    if( m_dummyPad->GetShape() == PAD_CIRCLE )
+        ysize = m_dummyPad->GetSize().x;
+    else
+        ysize = m_dummyPad->GetSize().y;
+
+    dim = ysize + std::abs( m_dummyPad->GetDelta().x );
+
+    // Invalid y size. See note about x size above.
+    if( dim == 0 )
+    {
+        dim = m_dummyPad->GetDrillSize().y;
+        if( dim == 0 )
+            dim = 1000000;
+    }
+
     if( m_dummyPad->GetLocalClearance() > 0 )
         dim += m_dummyPad->GetLocalClearance() * 2;
 
@@ -710,6 +738,12 @@ bool DIALOG_PAD_PROPERTIES::padValuesOK()
     wxString msg;
 
     // Test for incorrect values
+    if( (m_dummyPad->GetSize().x <= 0) ||
+       ((m_dummyPad->GetSize().y <= 0) && (m_dummyPad->GetShape() != PAD_CIRCLE)) )
+    {
+        error_msgs.Add( _( "Pad size must be greater than zero" ) );
+    }
+
     if( (m_dummyPad->GetSize().x < m_dummyPad->GetDrillSize().x) ||
         (m_dummyPad->GetSize().y < m_dummyPad->GetDrillSize().y) )
     {