(#6740) facter doesn't always respect facts in environment variables

On an OSX host:

    $ facter operatingsystem
    Darwin

    $ facter_operatingsystem=Not_Darwin facter operatingsystem
    Not_Darwin

But on a linux/solaris host:

    $ facter operatingsystem
    CentOS

    $ facter_operatingsystem=Not_CentOS facter operatingsystem
    CentOS

As the operatingsystem fact resolution for linux-based kernels has higher
precedence than the environment variable as it has more matching confines than
the value from the environment variable.

This patch adds from_environment to the resolution mechanism, which makes the
resolution have an artificially high weight by claiming the length of its
confines array is 1 billion.

2 files changed, 14 insertions, 1 deletions

diff --git a/lib/facter/util/loader.rb b/lib/facter/util/loader.rb
index 2d2d9e8..b6aa8de 100644
--- a/lib/facter/util/loader.rb
+++ b/lib/facter/util/loader.rb
@@ -90,6 +90,7 @@ class Facter::Util::Loader
             next if fact and env_name != fact
 
             Facter.add($1) do
+                from_environment
                 setcode { value }
             end
 
diff --git a/lib/facter/util/resolution.rb b/lib/facter/util/resolution.rb
index 4a99c35..2ca2447 100644
--- a/lib/facter/util/resolution.rb
+++ b/lib/facter/util/resolution.rb
@@ -85,17 +85,29 @@ class Facter::Util::Resolution
         end
     end
 
+    # Say this resolution came from the environment
+    def from_environment
+        @from_environment = true
+    end
+
     # Create a new resolution mechanism.
     def initialize(name)
         @name = name
         @confines = []
         @value = nil
         @timeout = 0
+        @from_environment = false
     end
 
     # Return the number of confines.
     def length
-        @confines.length
+        # If the resolution came from an environment variable
+        # say we're very very sure about the value of the resolution
+        if @from_environment
+            1_000_000_000
+        else
+            @confines.length
+        end
     end
 
     # We need this as a getter for 'timeout', because some versions