Merge remote-tracking branch 'origin/patch'

Author: ryanmkurtz

Ghidra/Features/CodeCompare/src/main/java/ghidra/codecompare/graphanalysis/DataGraph.java

@@ -201,9 +201,9 @@ private void eliminatePtrsubs(ArrayList<DataVertex> ptrsubs) {
 				DataVertex outNode = subop.sinks.get(0);
 				in1Node.sinks.clear();
 				replaceNodeInOutEdges(outNode, in1Node);
-				in0Node.clearEdges();
-				subop.clearEdges();
-				outNode.clearEdges();
+				in0Node.collapse();
+				subop.collapse();
+				outNode.collapse();
 				makeAssociation(subop, outNode, in1Node, 0);	// Attach subop and outNode -> in1Node
 			}
 		}
@@ -245,7 +245,7 @@ private void eliminateCasts(ArrayList<DataVertex> casts) {
 				out.sources.clear();
 				topOp.sinks.add(out);
 				out.sources.add(topOp);
-				in.clearEdges();
+				in.collapse();
 				if (assoc == null) {
 					assoc = out;
 				}
@@ -256,13 +256,13 @@ private void eliminateCasts(ArrayList<DataVertex> casts) {
 				// output is isolated
 				removeInEdge(castNode, 0);
 				replaceNodeInOutEdges(out, in);
-				out.clearEdges();
+				out.collapse();
 				if (assoc == null) {
 					assoc = in;
 				}
 				makeAssociation(castNode, out, assoc, assocSlot);
 			}
-			castNode.clearEdges();
+			castNode.collapse();
 		}
 	}
 
@@ -273,6 +273,9 @@ private void eliminateCasts(ArrayList<DataVertex> casts) {
 	public void makeNGrams(int numNGrams) {
 		for (int i = 0; i < numNGrams - 1; ++i) {
 			for (DataVertex node : nodeList) {
+				if (node.isCollapsed()) {
+					continue;					// Don't hash if disconnected from graph
+				}
 				node.nextNGramSource(i);		// Construct (n+1)-gram from existing n-gram
 			}
 		}

Ghidra/Features/CodeCompare/src/main/java/ghidra/codecompare/graphanalysis/DataVertex.java

@@ -98,11 +98,14 @@ public String toString() {
 	}
 
 	/**
-	 * Clear any incoming or outgoing edges to/from this node
+	 * Mark this node as disconnected from its graph.
+	 * Clear any incoming or outgoing edges to/from this node.
+	 * Clear the ngrams
 	 */
-	void clearEdges() {
+	void collapse() {
 		sinks.clear();
 		sources.clear();
+		ngrams.clear();
 	}
 
 	@Override
@@ -188,6 +191,13 @@ public boolean isOp() {
 		return (op != null);
 	}
 
+	/**
+	 * @return true if this node has been removed from its DataGraph
+	 */
+	public boolean isCollapsed() {
+		return (ngrams.size() == 0);
+	}
+
 	/**
 	 * Is the underlying node a PcodeOp which takes commutative inputs?
 	 * @return true if the PcodeOp is commutative