allow 4 different copying conditions in module descriptions

[Bruno Haible]

It appears to be consensus that the majority of gnulib modules will migrate
from GPLv2+ to GPLv3+ and from LGPLv2+ to LGPLv3+, respectively, but some
will stay at the existing copyright for some time.

This patch to gnulib-tool allows the shorthand notation "GPLv2+" to be used
as a synonym for "GPL" (which, as documented in gnulib-intro.texi, means
"GPL v2 or newer"), and "LGPLv2+" as a synonym for "LGPL" (which, as
there as well, means "LGPLv2 or newer").

Karl and other lawyers, watch: There is no license change being done here.
Just adding synonymous abbreviations.

The patch also introduces a bug: it gives a warning when you have a GPLv2+
module that depends on a GPL module, or when you have an LGPLv2+ module
that depends on an LGPL module. This is a bug.


2007-07-13  Bruno Haible  <address@hidden>

        * gnulib-tool (func_import): Treat LGPLv2 as synonymous to LGPL.
        (func_create_testdir): Handle copying terms "GPLv2+" and "LGPLv2+".

*** gnulib-tool 10 Jul 2007 12:25:38 -0000      1.246
--- gnulib-tool 13 Jul 2007 00:54:26 -0000
***************
*** 1940,1946 ****
      for module in $modules; do
        license=`func_get_license $module`
        case $license in
!         LGPL | 'GPLed build tool') ;;
          'public domain' | 'unlimited' | 'unmodifiable license text') ;;
          *) func_fatal_error "incompatible license on module $module: 
$license" ;;
        esac
--- 1940,1946 ----
      for module in $modules; do
        license=`func_get_license $module`
        case $license in
!         LGPL | LGPLv2+ | 'GPLed build tool') ;;
          'public domain' | 'unlimited' | 'unmodifiable license text') ;;
          *) func_fatal_error "incompatible license on module $module: 
$license" ;;
        esac
***************
*** 2655,2664 ****
        func_modules_transitive_closure
        for module in $modules; do
          license=`func_get_license "$module"`
!         case $license in
!           LGPL | 'GPLed build tool') ;;
            'public domain' | 'unlimited' | 'unmodifiable license text') ;;
!           *) echo "warning: module $requested_module depends on a module with 
an incompatible license: $module" 1>&2 ;;
          esac
        done
      fi
--- 2655,2685 ----
        func_modules_transitive_closure
        for module in $modules; do
          license=`func_get_license "$module"`
!         case "$license" in
!           'GPLed build tool') ;;
            'public domain' | 'unlimited' | 'unmodifiable license text') ;;
!           *)
!             case "$requested_license" in
!               GPLv2+)
!                 case "$license" in
!                   GPLv2+ | LGPLv2+) ;;
!                   *) echo "warning: module $requested_module depends on a 
module with an incompatible license: $module" 1>&2 ;;
!                 esac
!                 ;;
!               LGPL)
!                 case "$license" in
!                   LGPL | LGPLv2+) ;;
!                   *) echo "warning: module $requested_module depends on a 
module with an incompatible license: $module" 1>&2 ;;
!                 esac
!                 ;;
!               LGPLv2+)
!                 case "$license" in
!                   LGPLv2+) ;;
!                   *) echo "warning: module $requested_module depends on a 
module with an incompatible license: $module" 1>&2 ;;
!                 esac
!                 ;;
!             esac
!             ;;
          esac
        done
      fi