The window context variable is share by all tab and can get mix up when user navigate from one tab to another. This patch recreate the window context variable before entering a tab to solve the potential conflict issue.

Link to SF Tracker: http://sourceforge.net/support/tracker.php?aid=2959339

base/src/org/compiere/model/GridField.java

@@ -1278,6 +1278,19 @@ public class GridField
 		m_inserting = inserting;
 		m_error = false;        //  reset error
 
+		updateContext();
+
+		//  Does not fire, if same value
+		Object oldValue = m_oldValue;
+		if (inserting)
+			oldValue = INSERTING;
+		m_propertyChangeListeners.firePropertyChange(PROPERTY, oldValue, m_value);
+	}   //  setValue
+
+	/**
+	 * Update env. context with current value
+	 */
+	public void updateContext() {
 		//	Set Context
 		if (m_vo.displayType == DisplayType.Text 
 			|| m_vo.displayType == DisplayType.Memo
@@ -1286,15 +1299,15 @@ public class GridField
 			|| m_vo.displayType == DisplayType.RowID
 			|| isEncrypted())
 			;	//	ignore
-		else if (newValue instanceof Boolean)
+		else if (m_value instanceof Boolean)
 		{
 			backupValue(); // teo_sarca [ 1699826 ]
 			Env.setContext(m_vo.ctx, m_vo.WindowNo, m_vo.ColumnName, 
-				((Boolean)newValue).booleanValue());
+				((Boolean)m_value).booleanValue());
 			Env.setContext(m_vo.ctx, m_vo.WindowNo, m_vo.TabNo, m_vo.ColumnName, 
 					m_value==null ? null : (((Boolean)m_value) ? "Y" : "N"));
 		}
-		else if (newValue instanceof Timestamp)
+		else if (m_value instanceof Timestamp)
 		{
 			backupValue(); // teo_sarca [ 1699826 ]
 			Env.setContext(m_vo.ctx, m_vo.WindowNo, m_vo.ColumnName, (Timestamp)m_value);
@@ -1309,13 +1322,7 @@ public class GridField
 			Env.setContext(m_vo.ctx, m_vo.WindowNo, m_vo.TabNo, m_vo.ColumnName, 
 				m_value==null ? null : m_value.toString());
 		}		
-		
+	}
-		//  Does not fire, if same value
-		Object oldValue = m_oldValue;
-		if (inserting)
-			oldValue = INSERTING;
-		m_propertyChangeListeners.firePropertyChange(PROPERTY, oldValue, m_value);
-	}   //  setValue
 
 	/**
 	 * 	Set Value and Validate

zkwebui/WEB-INF/src/org/adempiere/webui/component/AbstractADTab.java

@@ -18,14 +18,18 @@
 package org.adempiere.webui.component;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
+import org.adempiere.webui.panel.ADSortTab;
 import org.adempiere.webui.panel.ADTabpanel;
 import org.adempiere.webui.panel.IADTabpanel;
 import org.adempiere.webui.part.AbstractUIPart;
 import org.compiere.model.DataStatusEvent;
+import org.compiere.model.GridField;
 import org.compiere.model.GridTab;
 import org.compiere.util.CLogger;
+import org.compiere.util.Env;
 import org.compiere.util.Evaluator;
 
 /**
@@ -119,6 +123,7 @@ public abstract class AbstractADTab extends AbstractUIPart implements IADTab
             canJump = canNavigateTo(oldIndex, newIndex);
             if (canJump) 
             {
+            	prepareContext(newIndex, newTab);
 	            doTabSelectionChanged(oldIndex, newIndex);
             }
         }
@@ -126,6 +131,59 @@ public abstract class AbstractADTab extends AbstractUIPart implements IADTab
         return canJump;
     }
     
+    private void prepareContext(int newIndex, IADTabpanel newTab) {
+		//update context
+		if (newTab != null)
+		{
+			List<Integer> parents = new ArrayList<Integer>();
+			//get parent list
+			if (newIndex > 0)
+			{
+				int currentLevel = newTab.getTabLevel();
+				for (int i = newIndex - 1; i >= 0; i--)
+				{
+					IADTabpanel adtab = tabPanelList.get(i);
+					if (adtab.getGridTab() == null) continue;
+					if (adtab instanceof ADSortTab) continue;
+					if (adtab.getTabLevel() < currentLevel || i == 0)
+					{
+						parents.add(i);
+						currentLevel = adtab.getTabLevel();
+					}
+				}
+				Collections.reverse(parents);
+			}
+
+			//clear context
+			for (int i = 0; i < tabPanelList.size(); i++)
+			{
+				IADTabpanel adtab = tabPanelList.get(i);
+				if (adtab.getGridTab() == null) continue;
+				if (adtab instanceof ADSortTab) continue;
+				GridField[] fields = adtab.getGridTab().getFields();
+				for (GridField gf : fields)
+				{
+					Env.setContext(Env.getCtx(), gf.getWindowNo(),  gf.getColumnName(), "");
+				}
+			}
+
+			//add parent value to context
+			if (!parents.isEmpty())
+			{
+				for(int i : parents)
+				{
+					IADTabpanel adtab = tabPanelList.get(i);
+
+					GridField[] fields = adtab.getGridTab().getFields();
+					for (GridField gf : fields)
+					{
+						gf.updateContext();
+					}
+				}
+			}
+		}
+	}
+
     protected abstract void doTabSelectionChanged(int oldIndex, int newIndex);
 
     public boolean isDisplay(int index) {