qpkg: regression test for version preference

- test/verpref: test version preference (higher wins if there's a choice)
- TODO: updated for above change

qpkg/TODO

@@ -7,8 +7,6 @@ Still left to do
 
 - handle Provides:
 
-- if there are multiple choices, try to prefer more recent versions
-
 - sort prerequisites such that they can be installed in the specified order
 
 - consider Architecture:
@@ -50,3 +48,5 @@ Done
 
   Update: after merging the two lookups per new node into one, we're at
   1172642 calls to comp_id, or 102% of the predicted "good case".
+
+- if there are multiple choices, try to prefer more recent versions

qpkg/test/verpref

@@ -0,0 +1,96 @@
+#!/bin/sh
+. ./Common
+
+###############################################################################
+
+qpkg "prefer later version (1)" prereq foo <<EOF
+Package: bar
+Version: 0
+Architecture: test
+Filename: bar_0
+
+Package: bar
+Version: 1
+Architecture: test
+Filename: bar_1
+
+Package: foo
+Version: 0
+Architecture: test
+Depends: bar
+Filename: foo
+EOF
+expect <<EOF
+bar_1
+EOF
+
+###############################################################################
+
+qpkg "prefer later version (2)" prereq foo <<EOF
+Package: bar
+Version: 1
+Architecture: test
+Filename: bar_1
+
+Package: bar
+Version: 0
+Architecture: test
+Filename: bar_0
+
+Package: foo
+Version: 0
+Architecture: test
+Depends: bar
+Filename: foo
+EOF
+expect <<EOF
+bar_1
+EOF
+
+###############################################################################
+
+qpkg "dependency trumps preference (1)" prereq foo <<EOF
+Package: bar
+Version: 0
+Architecture: test
+Filename: bar_0
+
+Package: bar
+Version: 1
+Architecture: test
+Depends: bad
+Filename: bar_1
+
+Package: foo
+Version: 0
+Architecture: test
+Depends: bar
+Filename: foo
+EOF
+expect <<EOF
+bar_0
+EOF
+
+###############################################################################
+
+qpkg "dependency trumps preference (2)" prereq foo <<EOF
+Package: bar
+Version: 1
+Architecture: test
+Depends: bad
+Filename: bar_1
+
+Package: bar
+Version: 0
+Architecture: test
+Filename: bar_0
+
+Package: foo
+Version: 0
+Architecture: test
+Depends: bar
+Filename: foo
+EOF
+expect <<EOF
+bar_0
+EOF