Catch :undefined_variable thrown when Future Parser is enabled with 3…

….7.x

lib/puppet/parser/functions/has_interface_with.rb

@@ -16,11 +16,11 @@ module Puppet::Parser::Functions
 
 If no "kind" is given, then the presence of the interface is checked:
 has_interface_with("lo")                        => true
-    EOS
+  EOS
   ) do |args|
 
     raise(Puppet::ParseError, "has_interface_with(): Wrong number of arguments " +
-          "given (#{args.size} for 1 or 2)") if args.size < 1 or args.size > 2
+        "given (#{args.size} for 1 or 2)") if args.size < 1 or args.size > 2
 
     interfaces = lookupvar('interfaces')
 
@@ -35,7 +35,13 @@ module Puppet::Parser::Functions
 
     kind, value = args
 
-    if lookupvar(kind) == value
+    # Bug with 3.7.1 - 3.7.3  when using future parser throws :undefined_variable
+    # https://tickets.puppetlabs.com/browse/PUP-3597
+    factval = nil
+    catch :undefined_variable do
+      factval = lookupvar(kind)
+    end
+    if factval == value
       return true
     end
 
@@ -44,15 +50,17 @@ module Puppet::Parser::Functions
       iface.downcase!
       factval = nil
       begin
-        factval = lookupvar("#{kind}_#{iface}")
+        # Bug with 3.7.1 - 3.7.3 when using future parser throws :undefined_variable
+        # https://tickets.puppetlabs.com/browse/PUP-3597
+        catch :undefined_variable do
+          factval = lookupvar("#{kind}_#{iface}")
+        end
+        if value == factval
+          result = true
+        end
       rescue Puppet::ParseError # Eat the exception if strict_variables = true is set
       end
-      if value == factval
-        result = true
-        break
-      end
     end
-
     result
   end
 end