[3.3] Bugfix: Creating a graph failed erroneously (v2) (#5898)

* Regression test & bugfix: comparison of edge definitions didn' order from and to

* Updated CHANGELOG

CHANGELOG

@@ -1,6 +1,10 @@
 v3.3.13 (XXXX-XX-XX)
 --------------------
 
+* fixed graph creation sometimes failing with 'edge collection
+  already used in edge def' when the edge definition contained multiple vertex
+  collections, despite the edge definitions being identical
+
 * inception could get caught in a trap, where agent configuration
   version and timeout multiplier lead to incapacitated agency
 

js/common/modules/@arangodb/general-graph.js

@@ -320,12 +320,20 @@ var transformExampleToAQL = function (examples, collections, bindVars, varname)
 // / internal helper to sort a graph's edge definitions
 // //////////////////////////////////////////////////////////////////////////////
 
-var sortEdgeDefinition = function (edgeDefinition) {
-  edgeDefinition.from = edgeDefinition.from.sort();
-  edgeDefinition.to = edgeDefinition.to.sort();
+var sortEdgeDefinitionInplace = function (edgeDefinition) {
+  edgeDefinition.from.sort();
+  edgeDefinition.to.sort();
   return edgeDefinition;
 };
 
+var sortEdgeDefinition = function (edgeDefinition) {
+  return {
+    collection: edgeDefinition.collection,
+    from: edgeDefinition.from.slice().sort(),
+    to: edgeDefinition.to.slice().sort(),
+  };
+};
+
 // //////////////////////////////////////////////////////////////////////////////
 // / @brief create a new graph
 // //////////////////////////////////////////////////////////////////////////////
@@ -729,6 +737,8 @@ var checkIfMayBeDropped = function (colName, graphName, graphs) {
 };
 
 const edgeDefinitionsEqual = function (leftEdgeDef, rightEdgeDef) {
+  leftEdgeDef = sortEdgeDefinition(leftEdgeDef);
+  rightEdgeDef = sortEdgeDefinition(rightEdgeDef);
   const stringify = obj => JSON.stringify(obj, Object.keys(obj).sort());
   return stringify(leftEdgeDef) === stringify(rightEdgeDef);
 };
@@ -781,7 +791,7 @@ class Graph {
 
     // Create Hidden Functions
     createHiddenProperty(this, '__updateBindCollections', updateBindCollections);
-    createHiddenProperty(this, '__sortEdgeDefinition', sortEdgeDefinition);
+    createHiddenProperty(this, '__sortEdgeDefinition', sortEdgeDefinitionInplace);
     updateBindCollections(self);
   }
 
@@ -1558,7 +1568,7 @@ class Graph {
 // //////////////////////////////////////////////////////////////////////////////
 
   _extendEdgeDefinitions (edgeDefinition) {
-    edgeDefinition = sortEdgeDefinition(edgeDefinition);
+    sortEdgeDefinitionInplace(edgeDefinition);
     var self = this;
     var err;
     // check if edgeCollection not already used
@@ -1632,7 +1642,7 @@ class Graph {
 // //////////////////////////////////////////////////////////////////////////////
 
   _editEdgeDefinitions (edgeDefinition) {
-    edgeDefinition = sortEdgeDefinition(edgeDefinition);
+    sortEdgeDefinitionInplace(edgeDefinition);
     var self = this;
 
     // check, if in graphs edge definition
@@ -2078,12 +2088,7 @@ exports._create = function (graphName, edgeDefinitions, orphanCollections, optio
     }
   );
 
-  edgeDefinitions.forEach(
-    (eD, index) => {
-      var tmp = sortEdgeDefinition(eD);
-      edgeDefinitions[index] = tmp;
-    }
-  );
+  edgeDefinitions.forEach(sortEdgeDefinitionInplace);
   orphanCollections = orphanCollections.sort();
 
   var data = gdb.save({

js/common/tests/shell/shell-general-graph.js

@@ -481,6 +481,9 @@ function GeneralGraphCreationSuite() {
     // definitions, which did rely on the edge definition object's key order
     // and thus sometimes reported spurious inequality.
     test_createGraphsWithOverlappingEdgeDefinitions: function () {
+      if (db._collection("_graphs").exists(gn)) {
+        db._collection("_graphs").remove(gn);
+      }
       // try to provoke differently ordered keys in
       // edge definitions that are actually equal.
       const edgeDefs1 = [
@@ -501,6 +504,35 @@ function GeneralGraphCreationSuite() {
       graph._create(gn2, edgeDefs2);
     },
 
+    // Graphs may have overlapping edge collections, as long as their
+    // definitions are equal.
+    // This is also a regression test for a broken comparison of edge
+    // definitions, which did rely on the edge definition's from and to
+    // arrays to be ordered.
+    test_createGraphsWithLargeOverlappingEdgeDefinitions: function () {
+      if (db._collection("_graphs").exists(gn)) {
+        db._collection("_graphs").remove(gn);
+      }
+      // try to provoke differently ordered from and to arrays in
+      // edge definitions that are actually equal.
+      const edgeDefs1 = [
+        {
+          collection: rn,
+          from: [vn1, vn2, vn3, vn4],
+          to: [vn2, vn1, vn4, vn3],
+        },
+      ];
+      const edgeDefs2 = [
+        {
+          collection: rn,
+          from: [vn4, vn3, vn2, vn1],
+          to: [vn3, vn4, vn1, vn2],
+        },
+      ];
+      graph._create(gn1, edgeDefs1);
+      graph._create(gn2, edgeDefs2);
+    },
+
     test_get_graph : function () {
       if (db._collection("_graphs").exists(gn)) {
         db._collection("_graphs").remove(gn);