Allow MSVC to build with Tcl 8.6.

Commit eaba54c20c5 added support for Tcl 8.6 for configure-supported
platforms after verifying that pltcl works without further changes, but
the MSVC tooling wasn't updated accordingly.  Update MSVC to match,
restructuring the code to avoid duplicating the logic for every Tcl
version supported.

Backpatch to all live branches, like eaba54c20c5.  In 9.4 and previous,
change the patch to use backslashes rather than forward, as in the rest
of the file.

Reported by Paresh More, who also tested the patch I provided.
Discussion: https://postgr.es/m/CAAgiCNGVw3ssBtSi3ZNstrz5k00ax=UV+_ZEHUeW_LMSGL2sew@mail.gmail.com

diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index b00be834fdedae598f57b93d11581648aecf5855..c8df68fc0868211e25402f5aa56df5e865b71a40 100644 (file)
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -180,20 +180,24 @@ sub mkvcbuild
 
    if ($solution->{options}->{tcl})
    {
+       my $found = 0;
        my $pltcl =
          $solution->AddProject('pltcl', 'dll', 'PLs', 'src/pl/tcl');
        $pltcl->AddIncludeDir($solution->{options}->{tcl} . '/include');
        $pltcl->AddReference($postgres);
-       if (-e $solution->{options}->{tcl} . '/lib/tcl85.lib')
-       {
-           $pltcl->AddLibrary(
-               $solution->{options}->{tcl} . '/lib/tcl85.lib');
-       }
-       else
+
+       for my $tclver (qw(86t 85 84))
        {
-           $pltcl->AddLibrary(
-               $solution->{options}->{tcl} . '/lib/tcl84.lib');
+           my $tcllib = $solution->{options}->{tcl} . "/lib/tcl$tclver.lib";
+           if (-e $tcllib)
+           {
+               $pltcl->AddLibrary($tcllib);
+               $found = 1;
+               last;
+           }
        }
+       die "Unable to find $solution->{options}->{tcl}/lib/tcl.lib"
+           unless $found;
    }
 
    $libpq = $solution->AddProject('libpq', 'dll', 'interfaces',