From 25b8673f84946b1072605137a4a1f60c89586489 Mon Sep 17 00:00:00 2001
From: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
Date: Sun, 15 Jan 2017 00:40:15 +0100
Subject: [PATCH] packages_tree: exact match trumps other providers

Ubuntu frequently has multiple providers for the same package name,
e.g. "vim" is provided by "vim", "vim-gnome" etc.

We need to adjust the resolving algorithm to:
1. lookup in virtual packages
2. lookup in packages
3. lookup in obsoletes.
Use the package which was found last (version-sorted).

Closes-bug: 1656888

Change-Id: I7279aa6526ff9133829be2e316932c9b052c7814
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
---
 packetary/objects/packages_tree.py | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/packetary/objects/packages_tree.py b/packetary/objects/packages_tree.py
index f02df59..0f6f045 100644
--- a/packetary/objects/packages_tree.py
+++ b/packetary/objects/packages_tree.py
@@ -68,25 +68,31 @@ class PackagesTree(object):
         :param version_range: the range of versions.
         :return: the list of suitable packages
         """
-        candidates = set()
-        # find package by name
-        if name in self.packages:
-            candidates.update(self.packages.find_all(name, version_range))
+        candidates = []
 
         # find package by provides
         # in case of rpm:
         #    set(candidates) >= set(provides)
         if name in self.provides:
-            candidates.update(self._resolve_relation(
-                self.provides[name], version_range)
-            )
+            candidates.extend(sorted(
+                self._resolve_relation(self.provides[name], version_range),
+                key=lambda x: x.version
+            ))
+
+        # find package by name
+        if name in self.packages:
+            candidates.extend(sorted(
+                self.packages.find_all(name, version_range),
+                key=lambda x: x.version
+            ))
 
         if name in self.obsoletes:
-            candidates.update(self._resolve_relation(
-                self.obsoletes[name], version_range)
-            )
+            candidates.extend(sorted(
+                self._resolve_relation(self.obsoletes[name], version_range),
+                key=lambda x: x.version
+            ))
 
-        return sorted(candidates, key=lambda x: x.version)
+        return candidates
 
     def get_unresolved_dependencies(self):
         """Gets the set of unresolved dependencies.