epkg-provided: exclude bundled libraries by default

Unless the new optional argument INCLUDE-BUNDLED is non-nil, return
no bundled libraries.

This also affects the return value of `epkg-reverse-dependencies',
which now no longer includes invalid reverse dependencies that are
due to a package bundling libraries it shouldn't be bundling.

That in turn affects `epkg-insert-reverse-dependencies', which is
used when presenting a package description.  This is what motivated
this change, but it also makes sense elsewhere.

epkg.el

@@ -288,17 +288,26 @@ for which one of these predicates returns non-nil."
 NAME is the name of a package, a string."
   (closql-get (epkg-db) name))
 
-(cl-defgeneric epkg-provided (package)
+(cl-defgeneric epkg-provided (package &optional include-bundled)
   "Return a list of features provided by PACKAGE.
-\n(fn PACKAGE)")
 
-(cl-defmethod  epkg-provided ((pkg epkg-package))
-  (epkg-provided (oref pkg name)))
+Bundled features are excluded from the returned list unless
+optional INCLUDE-BUNDLED is non-nil.
 
-(cl-defmethod  epkg-provided ((package string))
-  (mapcar #'car (epkg-sql [:select feature :from provided
-                           :where (= package $s1)
-                           :order-by [(asc feature)]] package)))
+\(fn PACKAGE &optional include-bundled)")
+
+(cl-defmethod  epkg-provided ((pkg epkg-package) &optional include-bundled)
+  (epkg-provided (oref pkg name) include-bundled))
+
+(cl-defmethod  epkg-provided ((package string) &optional include-bundled)
+  (mapcar #'car (if include-bundled
+                    (epkg-sql [:select feature :from provided
+                               :where (= package $s1)
+                               :order-by [(asc feature)]] package)
+                  (epkg-sql [:select feature :from provided
+                             :where (and (= package $s1)
+                                         (isnull drop))
+                             :order-by [(asc feature)]] package))))
 
 (cl-defgeneric epkg-required (package)
   "Return a list of packages and features required by PACKAGE.

epkg.org

@@ -435,12 +435,15 @@ Emacsmirror, but not in a client.  And the ~required~ slot only lists
 features but not the packages that provide them.  The following
 functions return these values in a form that is generally more useful.
 
-- Function: epkg-provided package
+- Function: epkg-provided package &optional include-bundled
 
   This function returns a list of features provided by the package
   PACKAGE.  PACKAGE is an ~epkg-package~ object or a package name, a
   string.
 
+  Bundled features are excluded from the returned list unless
+  optional INCLUDE-BUNDLED is non-nil.
+
 - Function: epkg-required package
 
   This function returns a list of packages and features required by

epkg.texi

@@ -527,11 +527,14 @@ Emacsmirror, but not in a client.  And the @code{required} slot only lists
 features but not the packages that provide them.  The following
 functions return these values in a form that is generally more useful.
 
-@defun epkg-provided package
+@defun epkg-provided package &optional include-bundled
 
 This function returns a list of features provided by the package
 PACKAGE.  PACKAGE is an @code{epkg-package} object or a package name, a
 string.
+
+Bundled features are excluded from the returned list unless
+optional INCLUDE-BUNDLED is non-nil.
 @end defun
 
 @defun epkg-required package