Improvements to SysGetEnvironmentList implementations

[lagprogramming]

packages/fcl-base/src/custapp.pp has the following procedure

Code: Pascal  [Select][+][-]

1. Procedure SysGetEnvironmentList(List : TStrings;NamesOnly : Boolean);
2.  
3. var
4.    s : string;
5.    i,j,count : longint;
6.  
7. begin
8.   count:=GetEnvironmentVariableCount;
9.   for j:=1 to count  do
10.     begin
11.     s:=GetEnvironmentString(j);
12.     If NamesOnly then
13.       begin
14.       I:=pos('=',s);
15.       If (I>1) then
16.         S:=Copy(S,1,I-1);
17.       end;
18.     List.Add(S);
19.     end;
20. end;

S:=Copy(S,1,I-1); has been replaced with SetLength(S,I-1);
After that, variables have been changed from longints to integers and named to uppercase in order to mimic the variable names of the other routines found in the same unit. Added and removed some spaces, too.
After that I've searched for Procedure SysGetEnvironmentList in the fpc directory in order to make sure the modified code looks like other procedures. So, I've had to replace S:=Copy(S,1,I-1); with S:=SetLength(S,I-1); in other routines, too. In addition to that, the OS2 version of SysGetEnvironmentList had a bug: the S variable was untyped.
The netwlibc version had the If (I>0) then condition instead of If (I>1) then. I've changed it to match all other implementations. It's this modification that I'd like FPC developers to double check. If NamesOnly was true, for a string like "=value", the original code would have considered an empty('') string as the name, in contradiction with the other implementations which would consider the entire "=value" string as a name. In this scenario, the modified code considers the entire "=value" line as the string name, as it is considered in all other implementations. I'd like FPC developers to make sure that this is the right behaviour.
Now all of them should look alike. Have a look and test.
I attach a patch with the following content:

Code: Pascal  [Select][+][-]

1. diff --git a/packages/fcl-base/src/custapp.pp b/packages/fcl-base/src/custapp.pp
2. index 45a37c8854..abc36a4ff4 100644
3. --- a/packages/fcl-base/src/custapp.pp
4. +++ b/packages/fcl-base/src/custapp.pp
5. @@ -183,22 +183,22 @@ function TCustomApplication.GetExeName: string;
6.  end;
7.  {$endif darwin}
8.  
9. -Procedure SysGetEnvironmentList(List : TStrings;NamesOnly : Boolean);
10. +Procedure SysGetEnvironmentList(List : TStrings; NamesOnly : Boolean);
11.  
12.  var
13. -   s : string;
14. -   i,j,count : longint;
15. +   S : String;
16. +   I,J,Count : Integer;
17.  
18.  begin
19. -  count:=GetEnvironmentVariableCount;
20. -  for j:=1 to count  do
21. +  Count:=GetEnvironmentVariableCount;
22. +  for J:=1 to Count do
23.      begin
24. -    s:=GetEnvironmentString(j);
25. +    S:=GetEnvironmentString(J);
26.      If NamesOnly then
27.        begin
28. -      I:=pos('=',s);
29. +      I:=Pos('=',S);
30.        If (I>1) then
31. -        S:=Copy(S,1,I-1);
32. +        SetLength(S,I-1);
33.        end;
34.      List.Add(S);
35.      end;
36. diff --git a/packages/fcl-base/src/go32v2/custapp.inc b/packages/fcl-base/src/go32v2/custapp.inc
37. index d684059fb9..9ef83aff17 100644
38. --- a/packages/fcl-base/src/go32v2/custapp.inc
39. +++ b/packages/fcl-base/src/go32v2/custapp.inc
40. @@ -13,7 +13,7 @@
41.  
42.   **********************************************************************}
43.  
44. -Procedure SysGetEnvironmentList(List : TStrings;NamesOnly : Boolean);
45. +Procedure SysGetEnvironmentList(List : TStrings; NamesOnly : Boolean);
46.  
47.  Var
48.    P : PPAnsiChar;
49. @@ -31,7 +31,7 @@
50.          begin
51.          I:=Pos('=',S);
52.          If (I>1) then
53. -          S:=Copy(S,1,I-1);
54. +          SetLength(S,I-1);
55.          end;
56.        List.Add(S);
57.        Inc(P);
58. diff --git a/packages/fcl-base/src/netwlibc/custapp.inc b/packages/fcl-base/src/netwlibc/custapp.inc
59. index 9911f3ed74..5bb53d8523 100644
60. --- a/packages/fcl-base/src/netwlibc/custapp.inc
61. +++ b/packages/fcl-base/src/netwlibc/custapp.inc
62. @@ -13,7 +13,7 @@
63.  
64.   **********************************************************************}
65.  
66. -Procedure SysGetEnvironmentList(List : TStrings;NamesOnly : Boolean);
67. +Procedure SysGetEnvironmentList(List : TStrings; NamesOnly : Boolean);
68.  
69.  Var
70.    P : PPAnsiChar;
71. @@ -30,8 +30,8 @@
72.        If NamesOnly then
73.          begin
74.          I:=Pos('=',S);
75. -        If (I>0) then
76. -          S:=Copy(S,1,I-1);
77. +        If (I>1) then
78. +          SetLength(S,I-1);
79.          end;
80.        List.Add(S);
81.        Inc(P);
82. diff --git a/packages/fcl-base/src/os2/custapp.inc b/packages/fcl-base/src/os2/custapp.inc
83. index 77224ca05f..a2561b383b 100644
84. --- a/packages/fcl-base/src/os2/custapp.inc
85. +++ b/packages/fcl-base/src/os2/custapp.inc
86. @@ -30,10 +30,10 @@ function EnvStr (Index: longint): ;
87.  end;
88.  
89.  
90. -procedure SysGetEnvironmentList(List : TStrings;NamesOnly : Boolean);
91. +procedure SysGetEnvironmentList(List : TStrings; NamesOnly : Boolean);
92.  
93.  Var
94. -  S : ;
95. +  S : String;
96.    J,I : Integer;
97.  
98.  begin
99. @@ -45,7 +45,7 @@ procedure SysGetEnvironmentList(List : TStrings;NamesOnly : Boolean);
100.        begin
101.        I:=Pos('=',S);
102.        If (I>1) then
103. -        S:=Copy(S,1,I-1);
104. +        SetLength(S,I-1);
105.        end;
106.      List.Add(S);
107.      end;

[AlexTP]

Posted to https://gitlab.com/freepascal.org/fpc/source/-/issues/40380