...raised exception class external SIGSEGV ??
lazarus / 16-Databases

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Elmug · 2012-06-29 01:36

SQLite3, one table, Grid application.

On a  self-learning application, I get to load the grid, edit, and add
records.

I can change the editable "select" clause to change the target table
fine, but only if I have not inserted records on the first table
opened.

When I insert a record, I commit and refresh. Then after two records
or so inserted as said, I edit the query so it calls for another table
in the database, and then get the error:
...raised exception class external SIGSEGV

Any suggestions on why this would be happening?

Thanks for any help afforded.

PS. The above is when running in the Lazarus environment.
When running the compiled .exe, the result is a Windows7 message:
Form1 is not responding.

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paweld · 2012-06-29 09:53

some source code?

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Kazmirus · 2012-11-26 21:34

I have the same problem but the exception came when I try to create
the form. First time I create the form Listatowarow is OK, secand time
is also OK but every next call to create cause the exception External
SIGSEGV at address 4101E6 and popup assembler debug window. I do not
know the assembler and cant catch the error by GDB.

...
    if JDBGridControl1.SelectedColumn.Index=0 then
     begin
         {Kartoteka}
          Listatowarow:=TListatowarow.create(Nil);   <-- External
SIGSEGV
          Listatowarow.showmodal;
          if Listatowarow.modalresult>0 then
             begin
...

This is source of the form Listatowarow

procedure TListatowarow.FormCreate(Sender: TObject);
var i:integer=0;
begin
  {********************************************}
  {****************** CREATE ******************}
  {********************************************}

  Dm.Magazyny.Open;
  Dm.Magazyny.First;
  DBLookupComboBox1.KeyValue:=Dm.MagazynyUID_MAGAZYNU.asinteger;

  Dm.Wykazkartotek.close;
  Dm.Wykazkartotek.SQL.Clear;
  Dm.Wykazkartotek.Sql.Add('select A.*, P.*, V.*, ');
  Dm.Wykazkartotek.Sql.Add('SUBSTRING(A.RODZAJ_CENY FROM 1 FOR 1)
NETTO, ');
  Dm.Wykazkartotek.Sql.Add('SUBSTRING(A.RODZAJ_CENY FROM 2 FOR 1) VAT,
');
  Dm.Wykazkartotek.Sql.Add('SUBSTRING(A.RODZAJ_CENY FROM 3 FOR 1)
BRUTTO  ');
  Dm.Wykazkartotek.Sql.Add(' from ');
  Dm.Wykazkartotek.Sql.Add(' KARTA_MAG A ');
  Dm.Wykazkartotek.Sql.Add(' LEFT OUTER JOIN PKWIU P ON
(A.UID_PKWIU=P.UID_PKWIU) ');
  Dm.Wykazkartotek.Sql.Add(' LEFT OUTER JOIN STAWKI_VAT V ON
(V.UID_STAWKIVAT=A.UID_STAWKIVAT) ');
  Dm.Wykazkartotek.Sql.Add('WHERE ');
  Dm.Wykazkartotek.Sql.Add('A.NAZWA_TOWARU LIKE ''%%''  ');
  Dm.Wykazkartotek.Sql.Add('AND
UID_MAGAZYNU='+vartostr(Dm.MagazynyUID_MAGAZYNU.asinteger));
  Dm.Wykazkartotek.Sql.Add('ORDER BY A.NAZWA_TOWARU ');
  Dm.Wykazkartotek.open;


  while i<3 do
  begin
    ComboBox1.Items.Add(Dbgrid1.Columns.Items.Title.Caption);
    inc(i);
  end;
  Combobox1.ItemIndex:=0;
end;

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Kazmirus · 2012-11-26 21:56

Quote from: Kazmirus on November 26, 2012, 10:34:00 pmI have the same
problem but the exception came when I try to create the form. First
time I create the form Listatowarow is OK, secand time is also OK but
every next call to create cause the exception External SIGSEGV at
address 4101E6 and popup assembler debug window. I do not know the
assembler and cant catch the error by GDB.

...
    if JDBGridControl1.SelectedColumn.Index=0 then
     begin
         {Kartoteka}
          Listatowarow:=TListatowarow.create(Nil);   <-- External
SIGSEGV
          Listatowarow.showmodal;
          if Listatowarow.modalresult>0 then
             begin
...

This is source of the form Listatowarow

procedure TListatowarow.FormCreate(Sender: TObject);
var i:integer=0;
begin
  {********************************************}
  {****************** CREATE ******************}
  {********************************************}

  Dm.Magazyny.Open;
  Dm.Magazyny.First;
  DBLookupComboBox1.KeyValue:=Dm.MagazynyUID_MAGAZYNU.asinteger;

  Dm.Wykazkartotek.close;
  Dm.Wykazkartotek.SQL.Clear;
  Dm.Wykazkartotek.Sql.Add('select A.*, P.*, V.*, ');
  Dm.Wykazkartotek.Sql.Add('SUBSTRING(A.RODZAJ_CENY FROM 1 FOR 1)
NETTO, ');
  Dm.Wykazkartotek.Sql.Add('SUBSTRING(A.RODZAJ_CENY FROM 2 FOR 1) VAT,
');
  Dm.Wykazkartotek.Sql.Add('SUBSTRING(A.RODZAJ_CENY FROM 3 FOR 1)
BRUTTO  ');
  Dm.Wykazkartotek.Sql.Add(' from ');
  Dm.Wykazkartotek.Sql.Add(' KARTA_MAG A ');
  Dm.Wykazkartotek.Sql.Add(' LEFT OUTER JOIN PKWIU P ON
(A.UID_PKWIU=P.UID_PKWIU) ');
  Dm.Wykazkartotek.Sql.Add(' LEFT OUTER JOIN STAWKI_VAT V ON
(V.UID_STAWKIVAT=A.UID_STAWKIVAT) ');
  Dm.Wykazkartotek.Sql.Add('WHERE ');
  Dm.Wykazkartotek.Sql.Add('A.NAZWA_TOWARU LIKE ''%%''  ');
  Dm.Wykazkartotek.Sql.Add('AND
UID_MAGAZYNU='+vartostr(Dm.MagazynyUID_MAGAZYNU.asinteger));
  Dm.Wykazkartotek.Sql.Add('ORDER BY A.NAZWA_TOWARU ');
  Dm.Wykazkartotek.open;


  while i<3 do
  begin
    ComboBox1.Items.Add(Dbgrid1.Columns.Items.Title.Caption);
    inc(i);
  end;
  Combobox1.ItemIndex:=0;
end;

The error I find in module LCL.

class function TLCLComponent.NewInstance: TObject;
begin
  Result := inherited NewInstance;   <--- Right here External SIGSEGV
  WSRegisterClass;

  TLCLComponent(Result).FWidgetSetClass :=
GetWSComponentClass(TLCLComponent(Result));
end;

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User137 · 2012-11-26 22:02

Is Listatowarow ever freed?

Also can you debug TListatowarow.FormCreate() line by line to see
where it stops? Could be some property from some visual component that
can't be accessed in formCreate (because they aren't showing yet).

edit: Use CODE tags. You can also edit your post, don't need to quote
it again.

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BlueIcaro · 2012-11-26 22:02

Try to change this line:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    
Listatowarow:=TListatowarow.create(Nil); 
for this one:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    
Listatowarow:=TListatowarow.create(Self); 
or this one:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    
Listatowarow:=TListatowarow.create(Application); /BlueIcaro

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Kazmirus · 2012-11-26 22:30

After debug it line by line..
The error I find in module LCL.

class function TLCLComponent.NewInstance: TObject;
begin
  Result := inherited NewInstance;   <--- Right here External SIGSEGV
  WSRegisterClass;

  TLCLComponent(Result).FWidgetSetClass :=
GetWSComponentClass(TLCLComponent(Result));
end; 

I tryed to use create(self), create(application) - the same error.

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Kazmirus · 2012-11-26 22:40

Yes the form Listatowarow is freed.
Sorry that you have to wait for my answer but the forum database is so
slow and additional I'm new here and I do not know all options how to
replay.

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paweld · 2012-11-27 12:14

On form ListaTowarow move code from event FormCreate to FormShow.

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