[Solved] ImageListEditor problem
lazarus / 9-Editor

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Bart · 2011-11-10 17:38

Hi,

I have a mysterious problem with my Lazarus.
When I open the ImageListEditor the ImageListEditor opens with the
Imagelist.
So far so good. The ImageListEditor shows up with the correct images
from the ImageList.

Now, whenI click on Add.. nothing happens (a TOpenPictureFileDialog is
supposed to open here).

This happened to me in r33269, when some days ago the same revision
worked perfectly.

I started Lazarus with a clean profile: no luck.
I rebuild Lazarus (clean + all): no luck.
I updated to r33459 and rebuilt (make clean all): no luck.

The bizarre part is that when I write a test program invoking the
ImageListEditor:

Code: [Select]procedure TForm1.Button1Click(Sender: TObject);
var
  ImageListEditorDlg: TImageListEditorDlg;
begin
    ImageListEditorDlg := TImageListEditorDlg.Create(Application);
    try
      ImageListEditorDlg.LoadFromImageList(ImageList1);
      if ImageListEditorDlg.ShowModal = mrOk then
        ImageListEditorDlg.SaveToImageList;
    finally
      ImageListEditorDlg.Free;
    end;
end;

This works perfectly: the ImageListEditor shows with the correct
images, and clicking the Add button shows a PictureOpenDialog, and I
can add pictures and they are saved in teh ImageList.

I then added some debugstatements to

Code: [Select]procedure TImageListEditorDlg.BtnAddClick(Sender:
TObject);
var
  I: Integer;
begin
  if OpenDialog.Execute then
  begin
    TreeView.BeginUpdate;
[snip]

And this showed me that OpenDialog.Execute returned False.

I then copied the lazarus.exe to another computer (where I first
updated to same revision and rebuild), and the ImageListEditor (in the
copied lazarus.exe) worked just fine.
I also copied the original lazarus.exe (built there) from the other
computer to mine, and the problem persists.

Does anyone have an idea?

Bart

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Blaazen · 2011-11-10 17:58

I have no such problems in r.33460 with Linux+Qt.
Maybe it is platform specific issue ?

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Bart · 2011-11-10 18:15

It may even be a problem with my computer.
The machine in question is a 11 year old Celeron system with WinME as
OS.
I have otherwise not experienced problems with any other applications
on this machine though.

The other computer (where all is fine) is a recent laptop with Win7.

It is really baffling me.

Bart

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Bart · 2011-11-11 11:50

Well, it is not my computer per se.
I narrowed it down to recent changes in paswstring.pas (A part of
LazUtils that  sets the widestringmanager for Lazarus).

All is fine up to r32966
The next revisions, r32967, r32972 (revisions of paswstring.pas) crash
Lazarus on startup.
In r32975 of paswstring.pas (which fixes the crash) the described bug
can be seen.

Now if I also use paswstring in my test project, the same error
occurs.
Actually OpenPictureDialog.Execute does not show the dialog anymore.

Here's some test code using the widestringmanager:

Code: [Select]procedure TForm1.Button2Click(Sender: TObject);
var
  S, S2: String;
  W, W2: WideString;
begin
  S := 'abc';
  S2 := Utf8UpperCase(S);
  W := 'xyz';
  W2 := WideUppercase(W);
  debugln('Utf8UpperCase(',S,') = ',S2);
  debugln('WideUppercase(',W,') = ',W2);
end; 

Output without using unit paswsrting (but with win9xwsmanager unit):

Code: [Select]Utf8UpperCase(abc) = ABC
WideUppercase(xyz) = XYZ

Output with use of paswstring unit (with or without win9xwsmanager)
Note I clicked the button twice this time, because of first result.

Code: [Select]Utf8UpperCase(abc) = ABC
WideUppercase(x+¦ ) = X+Ö  // x+¦  (on the left side) should be xyz
Utf8UpperCase(abc) = ABC
WideUppercase(xyZ) = XYZ   // xyZ  (on the left side) should be xyz
(note the capital Z)

Bart

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Bart · 2011-11-11 12:09

With r32978 (latest change in paswstring.pas) the reults are

Code: [Select]Utf8UpperCase(abc) = ABC
WideUppercase(x ) = X
Utf8UpperCase(abc) = ABC
WideUppercase(xyZ) = XYZ

Bart

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Bart · 2011-11-11 12:20

The horror starts right here!

Code: [Select]procedure TForm1.NormalBtnClick(Sender: TObject);
var
  S: String;
  W: WideString;
begin
  S := 'abc';
  W := 'xyz';
  debugln('S = ',S);
  debugln('W = ',W);
end;

Output:

Code: [Select]S = abc
W = xyC

Bart

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Bart · 2011-11-11 20:12

The problem is the wong implementation of Wide2AnsiMove()

Code: [Select]procedure Wide2AnsiMove(source:pwidechar;var
dest:ansistring;len:SizeInt);
var
  widestr: widestring;
begin
  {$ifdef PASWSTRING_VERBOSE}WriteLn('Wide2AnsiMove START');{$endif}
  // Copy the originating string taking into account the specified
length
  SetLength(widestr, len);
  System.Move(source^, widestr[1], len);

This should be replaced by
  System.Move(source^, widestr[1], len * SizeOf(WChar));

I created a bugreport and attached a patch in
http://bugs.freepascal.org/view.php?id=20668

Bart