Fixing #2541 - file cache is more resilient to failure

Signed-off-by: Luke Kanies <luke@madstop.com>

2 files changed, 42 insertions, 8 deletions

diff --git a/lib/puppet/util/autoload/file_cache.rb b/lib/puppet/util/autoload/file_cache.rb
index 12400f620..4ad0c7f39 100644
--- a/lib/puppet/util/autoload/file_cache.rb
+++ b/lib/puppet/util/autoload/file_cache.rb
@@ -23,7 +23,7 @@ module Puppet::Util::Autoload::FileCache
         cache = cached_data?(path, :directory?)
         return cache unless cache.nil?
 
-        begin
+        protect(path) do
             stat = File.lstat(path)
             if stat.directory?
                 found_file(path, stat)
@@ -32,9 +32,6 @@ module Puppet::Util::Autoload::FileCache
                 missing_file(path)
                 return false
             end
-        rescue Errno::ENOENT
-            missing_file(path)
-            return false
         end
     end
 
@@ -42,13 +39,10 @@ module Puppet::Util::Autoload::FileCache
         cache = cached_data?(path)
         return cache unless cache.nil?
 
-        begin
+        protect(path) do
             stat = File.lstat(path)
             found_file(path, stat)
             return true
-        rescue Errno::ENOENT
-            missing_file(path)
-            return false
         end
     end
 
@@ -108,4 +102,14 @@ module Puppet::Util::Autoload::FileCache
     def data_expired?(time)
         Time.now - time > 15
     end
+
+    def protect(path)
+        begin
+            yield
+        rescue => detail
+            raise unless detail.class.to_s.include?("Errno")
+            missing_file(path)
+            return false
+        end
+    end
 end
diff --git a/spec/unit/util/autoload/file_cache.rb b/spec/unit/util/autoload/file_cache.rb
index 333ddb545..59620ed2d 100755
--- a/spec/unit/util/autoload/file_cache.rb
+++ b/spec/unit/util/autoload/file_cache.rb
@@ -31,6 +31,21 @@ describe Puppet::Util::Autoload::FileCache do
             @cacher.should_not be_file_exist("/my/file")
         end
 
+        it "should consider a file as absent if the directory is absent" do
+            File.expects(:lstat).with("/my/file").raises Errno::ENOTDIR
+            @cacher.should_not be_file_exist("/my/file")
+        end
+
+        it "should consider a file as absent permissions are missing" do
+            File.expects(:lstat).with("/my/file").raises Errno::EACCES
+            @cacher.should_not be_file_exist("/my/file")
+        end
+
+        it "should raise non-fs exceptions" do
+            File.expects(:lstat).with("/my/file").raises ArgumentError
+            lambda { @cacher.file_exist?("/my/file") }.should raise_error(ArgumentError)
+        end
+
         it "should consider a file as present if its lstat succeeds" do
             File.expects(:lstat).with("/my/file").returns mock("stat")
             @cacher.should be_file_exist("/my/file")
@@ -87,6 +102,21 @@ describe Puppet::Util::Autoload::FileCache do
             @cacher.should_not be_directory_exist("/my/file")
         end
 
+        it "should consider a file as absent if the directory is absent" do
+            File.expects(:lstat).with("/my/file").raises Errno::ENOTDIR
+            @cacher.should_not be_directory_exist("/my/file")
+        end
+
+        it "should consider a file as absent permissions are missing" do
+            File.expects(:lstat).with("/my/file").raises Errno::EACCES
+            @cacher.should_not be_directory_exist("/my/file")
+        end
+
+        it "should raise non-fs exceptions" do
+            File.expects(:lstat).with("/my/file").raises ArgumentError
+            lambda { @cacher.directory_exist?("/my/file") }.should raise_error(ArgumentError)
+        end
+
         it "should consider a directory as present if its lstat succeeds and the stat is of a directory" do
             @stat.expects(:directory?).returns true
             File.expects(:lstat).with("/my/file").returns @stat