Fix: (descendants) matched against parent heading

It matched against parent headings instead of only descendants, which
caused some queries to return incorrect results.

Released as 0.2.1.

README.org

@@ -441,6 +441,11 @@ Expands into a call to ~org-ql-select~ with the same arguments.  For convenience
 
 /Note:/ Breaking changes may be made before version 1.0, but in the event of major changes, attempts at backward compatibility will be made with obsolescence declarations, translation of arguments, etc.  Users who need stability guarantees before 1.0 may choose to use tagged stable releases.
 
+** 0.2.1
+
+*Fixed*
++  =(descendants)= selector matched against parent heading instead of only descendants.
+
 ** 0.2
 :PROPERTIES:
 :ID:       67be09f9-e959-4333-9be2-93ad8f458fbe

org-ql.el

@@ -2,7 +2,7 @@
 
 ;; Author: Adam Porter <adam@alphapapa.net>
 ;; Url: https://github.com/alphapapa/org-ql
-;; Version: 0.2
+;; Version: 0.2.1
 ;; Package-Requires: ((emacs "26.1") (dash "2.13") (org "9.0") (s "1.12.0") (ts "0.2"))
 ;; Keywords: hypermedia, outlines, Org, agenda
 
@@ -683,6 +683,7 @@ Or, when possible, fix the problem."
     (save-restriction
       (org-narrow-to-subtree)
       (when (org-goto-first-child)
+        (narrow-to-region (point) (point-max))
         (catch 'found
           (org-ql-select (current-buffer)
             query

tests/test-org-ql.el

@@ -251,7 +251,13 @@ RESULTS should be a list of strings as returned by
           '("Test data" "Recurring")))
       (org-ql-it "with granddescendants query"
         (org-ql-expect ((descendants (descendants "moon")))
-          '("Test data" "Take over the universe" "Take over the moon" "Code"))))
+          '("Test data" "Take over the universe")))
+      (org-ql-it "with query that should not match parent"
+        ;; This test would fail if the `descendants' predicate did not properly exclude
+        ;; the parent heading by narrowing the buffer to begin at the first child.
+        (org-ql-expect ((and (descendants (todo "WAITING"))
+                             (not (descendants (todo "TODO" "NEXT")))))
+          '("Take over the moon"))))
 
     (describe "(clocked)"