Fix #1802 Exception with no-merge strategy in some cases. Incompatible edge should not be created

modules/ProcessorPlugin/src/main/java/org/gephi/io/processor/plugin/DefaultProcessor.java

@@ -228,27 +228,32 @@ public class DefaultProcessor extends AbstractProcessor {
 
             Edge edge = graph.getEdge(source, target, edgeType);
 
-            //Undirected and directed edges are incompatible, check for them or we could get an exception:
-            boolean canCreateEdge = true;
-            if (edge == null) {
-                if (createDirected) {
-                    //The edge may exist with opposite source-target but undirected. In that case we can't create a directed one:
-                    edge = graph.getEdge(target, source, edgeType);
-
-                    if (edge != null && edge.isDirected()) {
-                        edge = null;//Actually it's directed so we can create the opposite directed edge
-                    }
+            if (edgesMergeStrategy == EdgeMergeStrategy.NO_MERGE) {
+                //Undirected and directed edges are incompatible, check for them or we could get an exception:
+                final Edge incompatibleEdge = findIncompatibleEdge(graph, source, target, createDirected, edgeType);
+                if (incompatibleEdge == null) {
+                    //Force create, no merge
+                    edge = null;
                 } else {
-                    edge = graph.getEdge(target, source, edgeType);
+                    String message = NbBundle.getMessage(
+                            DefaultProcessor.class, "DefaultProcessor.error.incompatibleEdges",
+                            String.format(
+                                    "[%s -> %s; %s, type %s]",
+                                    sourceId, targetId, createDirected ? "Directed" : "Undirected", type
+                            ),
+                            String.format(
+                                    "[%s -> %s; %s; type: %s; id: %s]",
+                                    incompatibleEdge.getSource().getId(), incompatibleEdge.getTarget().getId(),
+                                    incompatibleEdge.isDirected() ? "Directed" : "Undirected",
+                                    incompatibleEdge.getTypeLabel(),
+                                    incompatibleEdge.getId()
+                            )
+                    );
+                    report.logIssue(new Issue(message, Issue.Level.WARNING));
+
+                    Progress.progress(progressTicket);
+                    continue;
                 }
-
-                if (edge != null) {
-                    canCreateEdge = false;
-                }
-            }
-
-            if (canCreateEdge && edgesMergeStrategy == EdgeMergeStrategy.NO_MERGE) {
-                edge = null;//Force create, no merge
             }
 
             boolean newEdge = edge == null;
@@ -286,6 +291,32 @@ public class DefaultProcessor extends AbstractProcessor {
         Progress.finish(progressTicket);
     }
 
+    private Edge findIncompatibleEdge(Graph graph, Node source, Node target, boolean directed, int edgeType) {
+        Edge edge = graph.getEdge(source, target, edgeType);
+
+        if (edge == null) {
+            if (directed) {
+                //The edge may exist with opposite source-target but undirected. In that case we can't create a directed one:
+                edge = graph.getEdge(target, source, edgeType);
+
+                if (edge != null && edge.isDirected()) {
+                    //Actually it's directed so we can create the opposite directed edge, not incompatible
+                    edge = null;
+                }
+            } else {
+                //Undirected but opposite edges are not compatible, check for it
+                edge = graph.getEdge(target, source, edgeType);
+            }
+        } else {
+            if (edge.isDirected() == directed) {
+                //Same directedness, not incompatible
+                edge = null;
+            }
+        }
+
+        return edge;
+    }
+
     private Object toElementId(ElementIdType elementIdType, String idString) {
         Object id;
         switch (elementIdType) {

modules/ProcessorPlugin/src/main/nbm/manifest.mf

 Manifest-Version: 1.0
 AutoUpdate-Essential-Module: true
 OpenIDE-Module-Localizing-Bundle: org/gephi/io/processor/plugin/Bundle.properties
-OpenIDE-Module-Specification-Version: ${gephi.modules.specification.version}
+OpenIDE-Module-Specification-Version: 0.9.2.1
 OpenIDE-Module-Display-Category: Plugin
 OpenIDE-Module-Name: Processor Plugin
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modules/ProcessorPlugin/src/main/resources/org/gephi/io/processor/plugin/Bundle.properties

@@ -10,4 +10,5 @@ AbstractProcessor.error.columnTypeMismatch=Existing column ''{0}'' in graph with
 AbstractProcessor.error.columnDefaultValueTypeMismatch=Column ''{0}'' default value ''{1}'' with type ''{2}'' is not compatible with the column type ''{3}''. Using null as default value.
 AbstractProcessor.error.unavailableColumnType=Attribute type ''{0}'' is unavailable for current time representation: {1}. Cannot add column with id ''{2}''.
 
-DefaultProcessor.error.configurationChangeForbidden=Cannot change graph configuration when the graph is not empty. Original configuration: {0}, new wanted configuration: {1}
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+DefaultProcessor.error.configurationChangeForbidden=Cannot change graph configuration when the graph is not empty. Original configuration: {0}, new wanted configuration: {1}
+DefaultProcessor.error.incompatibleEdges=No merge strategy was chosen but the edge {0} cannot be created because it can''t exist at the same time with edge {1} (incompatible). Skipping new edge.
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