* Patch from Sergei Gorelkin

  * TXPathUnionNode.Evaluate: fixed two crashes. The object returned by
    TXPathVariable.AsNodeSet is owned by that TXPathVariable and should
    not be explicitly destroyed. Also TXPathVariable should not be
    released if its AsNodeSet result will be used later.

  * TXPathLocationPathNode.Evaluate/EvaluateStep:

    - fixed crash in axisFollowing case branch (caused by wrong variable
      being used in the loop).
    - rewrote axisPreceding branch so it builds the result node list in
      correct (document) order.
    - Fixed predicate match condition that was always evaluating as True.

  * TXPathScanner.ParseLocationPath: modified so it never returns nil.
    This fixes crash in cases when '/' or '//' are used otherwise than
    the whole expression (e.g. 'string(/)').

  * Replaced manual searching in TList by calls to IndexOf() in two
    places.

git-svn-id: trunk@12934 -

packages/fcl-xml/src/xpath.pp

@@ -842,30 +842,25 @@ begin
     try
       NodeSet := Op1Result.AsNodeSet;
       NodeSet2 := Op2Result.AsNodeSet;
-      try
-        for i := 0 to NodeSet2.Count - 1 do
-        begin
-          DoAdd := True;
-          CurNode := NodeSet2[i];
-          for j := 0 to NodeSet.Count - 1 do
-            if NodeSet[j] = CurNode then
-            begin
-              DoAdd := False;
-          break;
-            end;
-          if DoAdd then
-            NodeSet.Add(CurNode);
-        end;
-      finally
-        NodeSet2.Free;
+      for i := 0 to NodeSet2.Count - 1 do
+      begin
+        DoAdd := True;
+        CurNode := NodeSet2[i];
+        for j := 0 to NodeSet.Count - 1 do
+          if NodeSet[j] = CurNode then
+          begin
+            DoAdd := False;
+            break;
+          end;
+        if DoAdd then
+          NodeSet.Add(CurNode);
       end;
     finally
       Op2Result.Release;
     end;
   finally
-    Op1Result.Release;
+    Result := Op1Result;
   end;
-  Result := TXPathNodeSetVariable.Create(NodeSet);
 end;
 
 
@@ -979,9 +974,6 @@ var
     StepNodes: TList;
 
     procedure DoNodeTest(Node: TDOMNode);
-    var
-      i: Integer;
-      DoAdd: Boolean;
     begin
       case AStep.NodeTestType of
         ntAnyPrincipal:
@@ -1002,14 +994,7 @@ var
           if Node.NodeType <> PROCESSING_INSTRUCTION_NODE then
             exit;
       end;
-      DoAdd := True;
-      for i := 0 to StepNodes.Count - 1 do
-        if TDOMNode(StepNodes[i]) = Node then
-        begin
-          DoAdd := False;
-          break;
-        end;
-      if DoAdd then
+      if StepNodes.IndexOf(Node) < 0 then
         StepNodes.Add(Node);
     end;
 
@@ -1030,12 +1015,12 @@ var
     Node, Node2: TDOMNode;
     Attr: TDOMNamedNodeMap;
     i, j: Integer;
-    DoAdd: Boolean;
 
     NewContext: TXPathContext;
     NewStepNodes: TNodeSet;
     Predicate: TXPathExprNode;
     PredicateResult: TXPathVariable;
+    TempList: TList;
 
   begin
     StepNodes := TList.Create;
@@ -1090,7 +1075,7 @@ var
             begin
               DoNodeTest(Node2);
               AddDescendants(Node2);
-              Node := Node.NextSibling;
+              Node2 := Node2.NextSibling;
             end;
             Node := Node.ParentNode;
           until not Assigned(Node);
@@ -1110,17 +1095,30 @@ var
           DoNodeTest(AContext.ContextNode);
       axisPreceding:
         begin
-          Node := AContext.ContextNode;
-          repeat
-            Node2 := Node.PreviousSibling;
-            while Assigned(Node2) do
+          TempList := TList.Create;
+          try
+            Node := AContext.ContextNode;
+            // build list of ancestors
+            while Assigned(Node) do
             begin
-              DoNodeTest(Node2);
-              AddDescendants(Node2);
-              Node := Node.PreviousSibling;
+              TempList.Add(Node);
+              Node := Node.ParentNode;
             end;
-            Node := Node.ParentNode;
-          until not Assigned(Node);
+            // then process it in reverse order
+            for i := TempList.Count-1 downto 1 do
+            begin
+              Node := TDOMNode(TempList[i]);
+              Node2 := Node.FirstChild;
+              while Assigned(Node2) and (Node2 <> TDOMNode(TempList[i-1])) do
+              begin
+                DoNodeTest(Node2);
+                AddDescendants(Node2);
+                Node2 := Node2.NextSibling;
+              end;
+            end;
+          finally
+            TempList.Free;
+          end;
         end;
       axisPrecedingSibling:
         begin
@@ -1158,7 +1156,8 @@ var
           try
             if (PredicateResult.InheritsFrom(TXPathNumberVariable) and
               (PredicateResult.AsNumber = j + 1)) or
-              PredicateResult.AsBoolean then
+              (not PredicateResult.InheritsFrom(TXPathNumberVariable) and
+               PredicateResult.AsBoolean) then
                 NewStepNodes.Add(Node);
           finally
             PredicateResult.Release;
@@ -1190,14 +1189,7 @@ var
       for i := 0 to StepNodes.Count - 1 do
       begin
         Node := TDOMNode(StepNodes[i]);
-        DoAdd := True;
-        for j := 0 to ResultNodeSet.Count - 1 do
-          if TDOMNode(ResultNodeSet[j]) = Node then
-          begin
-            DoAdd := False;
-            break;
-          end;
-        if DoAdd then
+        if ResultNodeSet.IndexOf(Node) < 0 then
           ResultNodeSet.Add(Node);
       end;
     end;
@@ -1628,7 +1620,7 @@ end;
 function TXPathScanner.ParseLocationPath: TXPathLocationPathNode;  // [1]
 var
   IsAbsolute, NeedColonColon: Boolean;
-  FirstStep, CurStep, NextStep: TStep;
+  CurStep, NextStep: TStep;
 
   procedure NeedBrackets;
   begin
@@ -1640,17 +1632,13 @@ var
 
 begin
   CurStep := nil;
-  Result := nil;
+  IsAbsolute := False;
 
   case CurToken of
     tkSlash:          // [2] AbsoluteLocationPath, first case
       begin
-        if NextToken = tkEndOfStream then
-          CurStep := TStep.Create(axisSelf, ntAnyNode)
-        else
-        if not (CurToken in
-          [tkDot, tkDotDot, tkAsterisk, tkAt, tkIdentifier, tkEndOfStream]) then
-          exit;
+        NextToken;
+        CurStep := TStep.Create(axisSelf, ntAnyNode);
         IsAbsolute := True;
       end;
     tkSlashSlash:     // [10] AbbreviatedAbsoluteLocationPath
@@ -1659,12 +1647,12 @@ begin
         IsAbsolute := True;
         CurStep := TStep.Create(axisDescendantOrSelf, ntAnyNode);
       end;
-    else
-      IsAbsolute := False;
   end;
 
+  Result := TXPathLocationPathNode.Create(IsAbsolute);
+  Result.FFirstStep := CurStep;
+
   // Parse [3] RelativeLocationPath
-  FirstStep := CurStep;
   repeat
     if CurToken <> tkEndOfStream then
     begin
@@ -1672,7 +1660,7 @@ begin
       if Assigned(CurStep) then
         CurStep.NextStep := NextStep
       else
-        FirstStep := NextStep;
+        Result.FFirstStep := NextStep;
       CurStep := NextStep;
     end;
 
@@ -1804,7 +1792,7 @@ begin
             end;
           tkEndOfStream:	// Enable support of "/" and "//" as path
         else
-          Error(SParserInvalidNodeTest);
+          Exit;
         end;
 
         // Parse predicates
@@ -1833,9 +1821,6 @@ begin
     else
       NextToken;   // skip the slash
   until False;
-
-  Result := TXPathLocationPathNode.Create(IsAbsolute);
-  Result.FFirstStep := FirstStep;
 end;
 
 function TXPathScanner.ParsePrimaryExpr: TXPathExprNode;  // [15]