fpspreadsheet: Improved auto-format detection (check extension first, check file header when extension test fails). Fix ods reader crashing when extension has been renamed.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6760 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/source/common/fpsopendocument.pas

@@ -2613,6 +2613,7 @@ begin
       XMLStream.Free;
     end;
 
+    if Assigned(Doc) then begin
       ReadFontFaces(Doc.DocumentElement.FindNode('office:font-face-decls'));
 
       StylesNode := Doc.DocumentElement.FindNode('office:styles');
@@ -2621,16 +2622,20 @@ begin
       ReadAutomaticStyles(Doc.DocumentElement.FindNode('office:automatic-styles'));
       ReadMasterStyles(Doc.DocumentElement.FindNode('office:master-styles'));
       FreeAndNil(Doc);
+    end;
 
     //process the content.xml file
     XMLStream := CreateXMLStream;
     try
       if UnzipToStream(AStream, 'content.xml', XMLStream) then
-        ReadXMLStream(Doc, XMLStream);
+        ReadXMLStream(Doc, XMLStream)
+      else
+        raise EFPSpreadsheetReader.CreateFmt(rsDefectiveInternalFileStructure, ['ods']);
     finally
       XMLStream.Free;
     end;
 
+    if Assigned(Doc) then begin
       ReadFontFaces(Doc.DocumentElement.FindNode('office:font-face-decls'));
       StylesNode := Doc.DocumentElement.FindNode('office:automatic-styles');
       ReadNumFormats(StylesNode);
@@ -2704,6 +2709,7 @@ begin
       end; //while Assigned(TableNode)
 
       FreeAndNil(Doc);
+    end;
 
     // process the settings.xml file (Note: it does not always exist!)
     XMLStream := CreateXMLStream;
@@ -2718,9 +2724,6 @@ begin
       XMLStream.Free;
     end;
 
-    // Convert formulas from OpenDocument to ExcelA1 dialect
-//    FixFormulas;
-
     // Active sheet
     if FActiveSheet <> '' then
       sheet := (FWorkbook as TsWorkbook).GetWorksheetByName(FActiveSheet) else

components/fpspreadsheet/source/common/fpspreadsheet.pas

@@ -8691,18 +8691,47 @@ procedure TsWorkbook.ReadFromFile(AFileName: string; APassword: String = '';
   AParams: TsStreamParams = []);
 var
   success: Boolean;
+  fmtID: TsSpreadFormatID;
   fileFormats: TsSpreadFormatIDArray;
   i: Integer;
+  found: Boolean;
 begin
   if not FileExists(AFileName) then
     raise EFPSpreadsheetReader.CreateFmt(rsFileNotFound, [AFileName]);
 
+  // First try to determine file format from the extension
+  if GetFormatFromFileName(AFilename, fmtID) then begin
+    try
+      ReadFromFile(AFileName, fmtID, APassword, AParams);
+      exit;
+    except
+      // format does not match. We must continue with rest of procedure
+    end;
+  end else
+    fmtID := MaxInt;
+
   // Try to get file format from file header
   GetFormatFromFileHeader(AFileName, fileformats);
   if Length(fileformats) = 0 then
     // If not successful use formats defined by extension
     fileFormats := GetSpreadFormatsFromFileName(faRead, AFileName);
 
+  // Remove already tested format
+  found := false;
+  i := 0;
+  while (i <= High(fileFormats)) do begin
+    if fileFormats[i] = fmtID then begin
+      found := true;
+      inc(i);
+      while (i <= High(fileFormats)) do begin
+        fileFormats[i-1] := fileFormats[i];
+        inc(i);
+      end;
+    end else
+     inc(i);
+  end;
+  if found then SetLength(fileFormats, Length(fileFormats)-1);
+
   // No file format found for this file --> error
   if Length(fileformats) = 0 then
     raise EFPSpreadsheetReader.CreateFmt(rsReaderNotFound, [AFileName]);

components/fpspreadsheet/source/common/fpsutils.pas

@@ -1370,7 +1370,7 @@ var
   fileformats: TsSpreadFormatIDArray;
 begin
   fileFormats := GetSpreadFormatsFromFileName(faRead, AFileName, ord(sfExcel8));
-  Result := (Length(fileFormats) > 0) and (fileFormats[0] <= sfidUnknown);
+  Result := (Length(fileFormats) > 0); // and (fileFormats[0] <= sfidUnknown);  // wp - removed for new format detection
   if Result then AFormatID := fileFormats[0];
 end;