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

[Graeme Geldenhuys]

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?


Regards,
  - Graeme -

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