fix and test execution of non-empty .bs files

During the build of XS modules, an empty Foo.bs file is normally created
for each Foo.so file. If a Foo_BS file is present, instead this triggers
the auto-generatation of a .bs file which may have executable perl
content.

However, nothing in core currently generates a non-empty .bs file.  So add
a test that this mechanism works, and fix up the three dynamic lib loaders
which implement the 'do $bs if -s $bs' mechanism to not rely on the
process having '.' present in @INC.

As it happens this already works currently, because the name of the
.bs file to load will usually be something like

    ../../lib/auto/Foo/Foo.bs

and the presence of the leading '..' causes 'do' to load the file directly
rather than via @INC.  But locally fix up @INC anyway, in case '../' isn't
always the case.

1 files changed, 2 insertions, 2 deletions

diff --git a/ext/DynaLoader/DynaLoader_pm.PL b/ext/DynaLoader/DynaLoader_pm.PL
index 24c8bea36c..bd95625822 100644
--- a/ext/DynaLoader/DynaLoader_pm.PL
+++ b/ext/DynaLoader/DynaLoader_pm.PL
@@ -85,7 +85,7 @@ package DynaLoader;
 # Tim.Bunce@ig.co.uk, August 1994
 
 BEGIN {
-    $VERSION = '1.41';
+    $VERSION = '1.42';
 }
 
 EOT
@@ -373,7 +373,7 @@ sub bootstrap {
     $bs =~ s/(\.\w+)?(;\d*)?$/\.bs/; # look for .bs 'beside' the library
     if (-s $bs) { # only read file if it's not empty
         print STDERR "BS: $bs ($^O, $dlsrc)\n" if $dl_debug;
-        eval { do $bs; };
+        eval { local @INC = ('.'); do $bs; };
         warn "$bs: $@\n" if $@;
     }