[CLOSED] Improvement of TApplication.IsRTLLang

[lagprogramming]

lcl/include/application.inc has

Code: Pascal  [Select][+][-]

1. function TApplication.IsRTLLang(const ALang: String): Boolean;
2. var
3.  lng : String;
4.  p   : word;
5.  
6.   function sep_pos : word; inline;
7.   begin
8.     Result := Pos('-', lng);
9.     if Result = 0 then
10.       Result := Pos('_', lng);
11.   end;
12.  
13. begin
14.   lng    := LowerCase(ALang);
15.   p      := sep_pos;
16.   if p > 0 then
17.     lng := copy(lng, 1, p-1);
18.  
19.   Result := (lng = 'ar') or // Arabic
20.             (lng = 'he') or // Hebrew
21.             (lng = 'yi') or // Yiddish
22.  
23.             // The languages bellow usually use arabic as the language name
24.             (lng = 'dv') or
25.             (lng = 'ps') or
26.             (lng = 'az') or
27.             (lng = 'fa') or
28.             (lng = 'ks') or
29.             (lng = 'ku') or
30.             (lng = 'pa') or
31.             (lng = 'sd') or
32.             (lng = 'tk') or
33.             (lng = 'ug') or
34.             (lng = 'ur') { or
35.  
36.               Not sure about the following languages ...
37.               They do not have 2 letters ISO standard are they in use ?
38.             (lng = 'jpr') or
39.             (lng = 'syr') or
40.             (lng = 'nqo') or
41.             (lng = 'jrb')
42.             }
43.             ;
44. end;

In order to match the result of the "Pos" function and the parameter of the "copy" function, variable "p" and nested function "sep_pos" have been changed from word to sizeint.
After that, the line "lng := copy(lng, 1, p-1);" has been replaced with "SetLength(lng, p-1);".
The modified function looks like this:

Code: Pascal  [Select][+][-]

1. function TApplication.IsRTLLang(const ALang: String): Boolean;
2. var
3.  lng : String;
4.  p   : SizeInt;
5.  
6.   function sep_pos : SizeInt; inline;
7.   begin
8.     Result := Pos('-', lng);
9.     if Result = 0 then
10.       Result := Pos('_', lng);
11.   end;
12.  
13. begin
14.   lng    := LowerCase(ALang);
15.   p      := sep_pos;
16.   if p > 0 then
17.     SetLength(lng, p-1);
18.  
19.   Result := (lng = 'ar') or // Arabic
20.             (lng = 'he') or // Hebrew
21.             (lng = 'yi') or // Yiddish
22.  
23.             // The languages bellow usually use arabic as the language name
24.             (lng = 'dv') or
25.             (lng = 'ps') or
26.             (lng = 'az') or
27.             (lng = 'fa') or
28.             (lng = 'ks') or
29.             (lng = 'ku') or
30.             (lng = 'pa') or
31.             (lng = 'sd') or
32.             (lng = 'tk') or
33.             (lng = 'ug') or
34.             (lng = 'ur') { or
35.  
36.               Not sure about the following languages ...
37.               They do not have 2 letters ISO standard are they in use ?
38.             (lng = 'jpr') or
39.             (lng = 'syr') or
40.             (lng = 'nqo') or
41.             (lng = 'jrb')
42.             }
43.             ;
44. end;

Here is the patch.

Code: Pascal  [Select][+][-]

1. diff --git a/lcl/include/application.inc b/lcl/include/application.inc
2. index 10abe008b0..4f3cfcfc9f 100644
3. --- a/lcl/include/application.inc
4. +++ b/lcl/include/application.inc
5. @@ -2464,9 +2464,9 @@ end;
6.  function TApplication.IsRTLLang(const ALang: String): Boolean;
7.  var
8.   lng : String;
9. - p   : word;
10. + p   : SizeInt;
11.  
12. -  function sep_pos : word; inline;
13. +  function sep_pos : SizeInt; inline;
14.    begin
15.      Result := Pos('-', lng);
16.      if Result = 0 then
17. @@ -2477,7 +2477,7 @@ begin
18.    lng    := LowerCase(ALang);
19.    p      := sep_pos;
20.    if p > 0 then
21. -    lng := copy(lng, 1, p-1);
22. +    SetLength(lng, p-1);
23.  
24.    Result := (lng = 'ar') or // Arabic
25.              (lng = 'he') or // Hebrew

[AlexTP]

Posted to https://gitlab.com/freepascal.org/lazarus/lazarus/-/issues/40469