Force encoding with timezones that include umlauts if zone encoding is IBM437 (#1781)

* If time.zone is encoded in Encoding::IBM437, force to WINDOWS_1252
* Added description of what's going on with the force/encode chain
* Handle umlauts in popen output from Mixlib shellout

Signed-off-by: Thomas Powell <powell@progress.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/lib/ohai/plugins/timezone.rb b/lib/ohai/plugins/timezone.rb
index 1d542e43..d2ab47dc 100644
--- a/lib/ohai/plugins/timezone.rb
+++ b/lib/ohai/plugins/timezone.rb
@@ -21,5 +21,25 @@ Ohai.plugin(:Timezone) do
   collect_data(:default) do
     time Mash.new unless time
     time[:timezone] = Time.now.getlocal.zone
+
+    # Windows in German display language outputs LATIN1 bytes for .zone, but marks them as
+    # IBM437, which somehow fails any attempt at conversion to other encodings when
+    # ä is present, as in the timezone name "Mitteleuropäische Zeit" (Central Europe Time)
+    #
+    # Windows-1252 is the legacy encoding for Windows for German that actually
+    # translates (ISO-8859-1 works as well), but going with the more correct
+    # encoding name for Windows' implementation of Latin-1
+    #
+    # References
+    # * [Code Page 437/IBM437](https://en.wikipedia.org/wiki/Code_page_437)
+    # * [ISO/IEC 8859-1](https://en.wikipedia.org/wiki/ISO/IEC_8859-1)
+    # * [Windows-1252](https://en.wikipedia.org/wiki/Windows-1252)
+    if time[:timezone].encoding == Encoding::IBM437
+      # Assume encoding is WINDOWS_1252
+      time[:timezone] = time[:timezone].force_encoding(Encoding::WINDOWS_1252)
+      # Re-encode in UTF_8. Note: If other encodings have problems converting
+      # it might be worth re-encode everything in UTF_8.
+      time[:timezone] = time[:timezone].encode(Encoding::UTF_8)
+    end
   end
 end