Add support for specifying individual paths of imported targets

The new config.import.* variable format is:

config.import.<proj>.<name>[.<type>]

For example:

b config.import.build2.b=/opt/build2/bin/b
b config.import.build2.b.exe=b-boot

1 files changed, 1 insertions, 2 deletions

diff --git a/build2/dist/operation.cxx b/build2/dist/operation.cxx
index cb3a6f3..9bb546c 100644
--- a/build2/dist/operation.cxx
+++ b/build2/dist/operation.cxx
@@ -156,12 +156,11 @@ namespace build2
                         ? out_src (d, rs)
                         : dir_path ());
 
-          const char* e (p.extension ());
           targets.insert<buildfile> (
             move (d),
             move (out),
             p.leaf ().base ().string (),
-            &extension_pool.find (e == nullptr ? "" : e), // Specified.
+            &extension_pool.find (p.extension ()), // Specified.
             trace);
         }
       };