Details
Minor Description
The comment of the method "selectSingleton" of the "StatefulResolver"[1] explains that the highest bundle revision is selected but it seems that the lowest singleton bundle revision is selected.
Given the following bundles:
// Bundle-SymbolicName: exporter; singleton:=true
// Bundle-Version: 1.0.0
// Export-Package: a
// Bundle-SymbolicName: exporter; singleton:=true
// Bundle-Version: 2.0.0
// Export-Package: b
// Bundle-SymbolicName: importer
// Bundle-Version: 1.0.0
// Import-Package: a
// Bundle-SymbolicName: importer
// Bundle-Version: 2.0.0
// Import-Package: b
When bundle importer-2.0.0 is started, a bundle exception is thrown (missing requirement), although the required package is provided by the highest singleton bundle revision (exporter-2.0.0).
When bundle importer-1.0.0 is started,it resolves, although the required package is provided by the lowest singleton bundle revision (exporter-1.0.0).
This is the output from the console that shows the above:
g! lb
START LEVEL 1
ID|State |Level|Name
0|Active | 0|System Bundle (4.2.1)
1|Active | 1|Apache Felix Bundle Repository (1.6.6)
2|Active | 1|Apache Felix Gogo Command (0.12.0)
3|Active | 1|Apache Felix Gogo Runtime (0.10.0)
4|Active | 1|Apache Felix Gogo Shell (0.10.0)
5|Installed | 1|importer (1.0.0)
6|Installed | 1|importer (2.0.0)
7|Installed | 1|exporter (1.0.0)
8|Installed | 1|exporter (2.0.0)
g! start 6
org.osgi.framework.BundleException: Unresolved constraint in bundle importer [6]: Unable to resolve 6.0: missing requirement [6.0] osgi.wiring.package; (osgi.wiring.package=b)
g! start 5
g! lb
START LEVEL 1
ID|State |Level|Name
0|Active | 0|System Bundle (4.2.1)
1|Active | 1|Apache Felix Bundle Repository (1.6.6)
2|Active | 1|Apache Felix Gogo Command (0.12.0)
3|Active | 1|Apache Felix Gogo Runtime (0.10.0)
4|Active | 1|Apache Felix Gogo Shell (0.10.0)
5|Active | 1|importer (1.0.0)
6|Installed | 1|importer (2.0.0)
7|Resolved | 1|exporter (1.0.0)
8|Installed | 1|exporter (2.0.0)
I am not sure about the desired behavior, but there is a discrepancy between the code and the comment.
If the comment describes the wanted behavior it can be achieved by replacing "(selected.getVersion().compareTo(singleton.getVersion()) > 0"[2] with "(singleton.getVersion().compareTo(selected.getVersion()) > 0", or with "(selected.getVersion().compareTo(singleton.getVersion()) < 0"
[1] http://svn.apache.org/viewvc/felix/releases/org.apache.felix.framework-4.2.1/src/main/java/org/apache/felix/framework/StatefulResolver.java?view=markup#l1361
[2] http://svn.apache.org/viewvc/felix/releases/org.apache.felix.framework-4.2.1/src/main/java/org/apache/felix/framework/StatefulResolver.java?view=markup#l1385