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xmlread.pp:
+ New option TDOMParseOptions.DisallowDoctype - prohibits processing of the DTD (specs compliant, targeted for SOAP applications). + New option TDOMParseOptions.MaxChars - limits max document length, protects against entity expansion attacks and DoS by feeding in too long documents. Default value of 0 means no restrictions. Tested with internal and external general entities, TBD with parameter entities. * Fixed calculation of URIs used to retrieve external entities, they should be evaluated at the point of entity declaration rather than at the point of resolving (which happens at the first inclusion). dom.pp: * TDOMNode.SetReadOnly, calling Attributes was causing creation of TAttributeMap on every element. Fixed. git-svn-id: trunk@13313 -
This commit is contained in:
sergei
parent
c21d5765ac
commit
09867a1f6e
@ -1097,9 +1097,9 @@ begin
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child.SetReadOnly(Value);
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child := child.NextSibling;
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end;
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attrs := Attributes;
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if Assigned(attrs) then
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if HasAttributes then
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begin
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attrs := Attributes;
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for I := 0 to attrs.Length-1 do
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attrs[I].SetReadOnly(Value);
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end;
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@ -66,6 +66,8 @@ type
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FCDSectionsAsText: Boolean;
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FResolveExternals: Boolean;
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FNamespaces: Boolean;
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FDisallowDoctype: Boolean;
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FMaxChars: Cardinal;
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public
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property Validate: Boolean read FValidate write FValidate;
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property PreserveWhitespace: Boolean read FPreserveWhitespace write FPreserveWhitespace;
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@ -74,6 +76,8 @@ type
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property CDSectionsAsText: Boolean read FCDSectionsAsText write FCDSectionsAsText;
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property ResolveExternals: Boolean read FResolveExternals write FResolveExternals;
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property Namespaces: Boolean read FNamespaces write FNamespaces;
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property DisallowDoctype: Boolean read FDisallowDoctype write FDisallowDoctype;
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property MaxChars: Cardinal read FMaxChars write FMaxChars;
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end;
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// NOTE: DOM 3 LS ACTION_TYPE enumeration starts at 1
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@ -162,7 +166,9 @@ type
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FOnStack: Boolean;
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FBetweenDecls: Boolean;
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FReplacementText: DOMString;
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FURI: DOMString;
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FStartLocation: TLocation;
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FCharCount: Cardinal;
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end;
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PWideCharBuf = ^TWideCharBuf;
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@ -186,6 +192,7 @@ type
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FXML11Rules: Boolean;
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FSystemID: WideString;
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FPublicID: WideString;
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FCharCount: Cardinal;
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function GetSystemID: WideString;
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function GetPublicID: WideString;
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protected
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@ -355,6 +362,8 @@ type
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FCDSectionsAsText: Boolean;
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FResolveExternals: Boolean;
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FNamespaces: Boolean;
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FDisallowDoctype: Boolean;
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FMaxChars: Cardinal;
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procedure RaiseExpectedQmark;
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procedure Initialize(ASource: TXMLCharSource);
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@ -373,6 +382,7 @@ type
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procedure CallErrorHandler(E: EXMLReadError);
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function FindOrCreateElDef: TDOMElementDef;
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function SkipUntilSeq(const Delim: TSetOfChar; const More: array of WideChar): Boolean;
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procedure CheckMaxChars;
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protected
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FCursor: TDOMNode_WithChildren;
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FNesting: Integer;
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@ -424,7 +434,7 @@ type
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procedure ExpectChoiceOrSeq(CP: TContentParticle);
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procedure ParseElementDecl;
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procedure ParseNotationDecl;
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function ResolveEntity(const SystemID, PublicID: WideString; out Source: TXMLCharSource): Boolean;
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function ResolveEntity(const AbsSysID, PublicID: WideString; out Source: TXMLCharSource): Boolean;
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procedure ProcessDefaultAttributes(Element: TDOMElement; Map: TDOMNamedNodeMap);
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procedure ProcessNamespaceAtts(Element: TDOMElement);
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procedure AddBinding(Attr: TDOMAttr; Prefix: PHashItem; var Chain: TBinding);
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@ -796,6 +806,7 @@ begin
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FBuf := PWideChar(AData);
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FBufEnd := FBuf + Length(AData);
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LFPos := FBuf-1;
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FCharCount := Length(AData);
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end;
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procedure TXMLCharSource.Initialize;
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@ -948,7 +959,12 @@ begin
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if rslt = 0 then
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Break
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else if rslt < 0 then
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DecodingError('Invalid character in input stream');
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DecodingError('Invalid character in input stream')
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else
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begin
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Inc(FCharCount, rslt);
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FReader.CheckMaxChars;
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end;
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until False;
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FBufEnd^ := #0;
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@ -1153,20 +1169,14 @@ begin
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Loc.LinePos := FSource.FBuf-FSource.LFPos;
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end;
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function TXMLReader.ResolveEntity(const SystemID, PublicID: WideString; out Source: TXMLCharSource): Boolean;
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function TXMLReader.ResolveEntity(const AbsSysID, PublicID: WideString; out Source: TXMLCharSource): Boolean;
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var
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AbsSysID: WideString;
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Filename: string;
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Stream: TStream;
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fd: THandle;
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begin
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Source := nil;
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Result := False;
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if not Assigned(FSource) then
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AbsSysID := SystemID
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else
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if not ResolveRelativeURI(FSource.SystemID, SystemID, AbsSysID) then
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Exit;
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{ TODO: alternative resolvers
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These may be 'internal' resolvers or a handler set by application.
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Internal resolvers should probably produce a TStream
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@ -1256,6 +1266,23 @@ begin
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E.Free;
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end;
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procedure TXMLReader.CheckMaxChars;
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var
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src: TXMLCharSource;
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total: Cardinal;
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begin
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if FMaxChars = 0 then
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Exit;
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src := FSource;
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total := 0;
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repeat
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Inc(total, src.FCharCount);
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if total > FMaxChars then
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FatalError('Exceeded character count limit');
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src := src.FParent;
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until src = nil;
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end;
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procedure TXMLReader.CallErrorHandler(E: EXMLReadError);
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begin
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try
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@ -1402,6 +1429,8 @@ begin
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FIgnoreComments := FCtrl.Options.IgnoreComments;
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FResolveExternals := FCtrl.Options.ResolveExternals;
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FNamespaces := FCtrl.Options.Namespaces;
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FDisallowDoctype := FCtrl.Options.DisallowDoctype;
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FMaxChars := FCtrl.Options.MaxChars;
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end;
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destructor TXMLReader.Destroy;
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@ -1696,7 +1725,7 @@ var
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begin
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if AEntity.SystemID <> '' then
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begin
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Result := ResolveEntity(AEntity.SystemID, AEntity.PublicID, Src);
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Result := ResolveEntity(AEntity.FURI, AEntity.PublicID, Src);
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if not Result then
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begin
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// TODO: a detailed message like SysErrorMessage(GetLastError) would be great here
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@ -1731,6 +1760,7 @@ begin
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if Assigned(FSource.FEntity) then
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begin
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TDOMEntityEx(FSource.FEntity).FOnStack := False;
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TDOMEntityEx(FSource.FEntity).FCharCount := FSource.FCharCount;
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// [28a] PE that was started between MarkupDecls may not end inside MarkupDecl
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Error := TDOMEntityEx(FSource.FEntity).FBetweenDecls and FInsideDecl;
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end;
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@ -1748,9 +1778,11 @@ var
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RefName: WideString;
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Child: TDOMNode;
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SaveCursor: TDOMNode_WithChildren;
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cnt: Cardinal;
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begin
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AEntity := nil;
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SetString(RefName, FName.Buffer, FName.Length);
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cnt := FName.Length+2;
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if Assigned(FDocType) then
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AEntity := FDocType.Entities.GetNamedItem(RefName) as TDOMEntityEx;
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@ -1758,19 +1790,19 @@ begin
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if AEntity = nil then
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begin
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if FStandalone or (FDocType = nil) or not (FHavePERefs or (FDocType.SystemID <> '')) then
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FatalError('Reference to undefined entity ''%s''', [RefName], FName.Length+2)
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FatalError('Reference to undefined entity ''%s''', [RefName], cnt)
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else
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ValidationError('Undefined entity ''%s'' referenced', [RefName], FName.Length+2);
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ValidationError('Undefined entity ''%s'' referenced', [RefName], cnt);
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FCursor.AppendChild(doc.CreateEntityReference(RefName));
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Exit;
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end;
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if InAttr and (AEntity.SystemID <> '') then
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FatalError('External entity reference is not allowed in attribute value', FName.Length+2);
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FatalError('External entity reference is not allowed in attribute value', cnt);
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if FStandalone and AEntity.FExternallyDeclared then
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FatalError('Standalone constraint violation', FName.Length+2);
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FatalError('Standalone constraint violation', cnt);
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if AEntity.NotationName <> '' then
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FatalError('Reference to unparsed entity ''%s''', [RefName], FName.Length+2);
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FatalError('Reference to unparsed entity ''%s''', [RefName], cnt);
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if not AEntity.FResolved then
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begin
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@ -1796,6 +1828,9 @@ begin
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end;
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end;
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end;
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// charcount of the entity included is known at this point
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Inc(FSource.FCharCount, AEntity.FCharCount - cnt);
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CheckMaxChars;
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if (not FExpandEntities) or (not AEntity.FResolved) then
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begin
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// This will clone Entity children
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@ -2071,9 +2106,12 @@ end;
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procedure TXMLReader.ParseDoctypeDecl; // [28]
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var
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Src: TXMLCharSource;
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DoctypeURI: WideString;
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begin
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if FState >= rsDTD then
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FatalError('Markup declaration is not allowed here');
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if FDisallowDoctype then
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FatalError('Document type is prohibited by parser settings');
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ExpectString('DOCTYPE');
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SkipS(True);
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@ -2111,7 +2149,8 @@ begin
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if (FDocType.SystemID <> '') then
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begin
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if ResolveEntity(FDocType.SystemID, FDocType.PublicID, Src) then
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ResolveRelativeURI(FSource.SystemID, FDocType.SystemID, DoctypeURI);
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if ResolveEntity(DocTypeURI, FDocType.PublicID, Src) then
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begin
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Initialize(Src);
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try
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@ -2541,8 +2580,13 @@ begin
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SetString(Entity.FReplacementText, FEntityValue.Buffer, FEntityValue.Length);
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end
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else
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begin
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if not ParseExternalID(Entity.FSystemID, Entity.FPublicID, False) then
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FatalError('Expected entity value or external ID');
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{ need to resolve entity's SystemID relative to the current source,
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which may differ from the source at the point of inclusion }
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ResolveRelativeURI(FSource.SystemID, Entity.SystemID, Entity.FURI);
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end;
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if NDataAllowed then // [76]
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begin
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