[fpc-devel] SqlDB + Firebird application doesn't run on new Ubuntu installation

[Michael Van Canneyt]

On Fri, 27 Nov 2009, Graeme Geldenhuys wrote:

> OK, below is one example of a patch, but there are alternative methods
> too, hence I am first posting here in the mailing list before I
> officially put something in Mantis.
>
> In the example below (which does work) I simply test for the newest
> major version first, then un-versioned, then backward compatibility library.
>
> ----------------------------------------
> diff --git a/packages/ibase/src/ibase60.inc b/packages/ibase/src/ibase60.inc
> index 5bc668d..54e2ab3 100644
> --- a/packages/ibase/src/ibase60.inc
> +++ b/packages/ibase/src/ibase60.inc
> @@ -2647,8 +2647,9 @@ begin
>     end
>   else
>     begin
> -    If (TryInitialiseIBase60(fbclib)=0) and
> -       (TryInitialiseIBase60(gdslib)=0) then
> +    If (TryInitialiseIBase60(fbclib+'.2')=0) and    // major versioned
> +       (TryInitialiseIBase60(fbclib)=0) and         // un-versioned
> +       (TryInitialiseIBase60(gdslib)=0) then        // backward
> compatibility
>         Raise EInOutError.CreateFmt(SErrDefaultsFailed,[gdslib,fbclib]);
>     end;
>   Result := RefCount;
> ----------------------------------------
>
>
> What I don't like about the patch above, is the 'and' statement.
> Wouldn't it be better (optimised) to do the following:
>
>  if not v2 found then                // libfbclient.so.2
>    if not unversioned found then     // libfbclient.so
>      if not gds found then           // libgds.so
>         raise Exception.Create(...)
>
> That way it will stop at the first if that found a valid library. Yet
> another alternative to the above if statement, is to test for the
> unversioned library first - this should make Joost happy & non-Ubuntu
> installs. That way DB developers could simply adjust the unversioned
> library symlink (libfbclient.so) and FPC would automatically load the
> developers desired version of the library. I think this is the best
> option so far.  eg:
>
>
>  if not unversioned found then      // libfbclient.so
>    if not v2 found then             // libfbclient.so.2
>      if not gds found then          // libgds.so
>         raise Exception.Create(...)
>
>
> Your thoughts?

I'd use an array of library names and a for loop. 
It is easier to extend. You can add fbclient.1 and
fbclient.3 to the array.

Michael.