(#5261) Fix #5261 Don't escape Unicode characters in PSON

This patch removes the escaping of valid UTF-8 sequences as "\uXXXX".
This code was unreliable, as it relied on Iconv's ability to convert
those codepoints between UTF-8 and UTF-16, but some versions of Iconv
barf on some valid codepoints.

Invalid UTF-8 sequences are still passed through unchanged. We believe
that this is fine; if you are concerned about complience with the JSON
standard, what we are doing is equivalent to:
  * interpreting binary files as Latin-1 encoded character sequences
  * JSON-encoding those characters according to RFC 4627
  * outputting the JSON as Latin-1
This allows all raw binary files to be transmitted losslessly.

Paired-With: Paul Berry <paul@puppetlabs.com>

2 files changed, 16 insertions, 22 deletions

diff --git a/lib/puppet/external/pson/pure/generator.rb b/lib/puppet/external/pson/pure/generator.rb
index 4180be57d..89a0c62e0 100644
--- a/lib/puppet/external/pson/pure/generator.rb
+++ b/lib/puppet/external/pson/pure/generator.rb
@@ -44,34 +44,13 @@ module PSON
       string << '' # XXX workaround: avoid buffer sharing
       string.force_encoding(Encoding::ASCII_8BIT)
       string.gsub!(/["\\\x0-\x1f]/) { MAP[$MATCH] }
-      string.gsub!(/(
-        (?:
-          [\xc2-\xdf][\x80-\xbf]    |
-          [\xe0-\xef][\x80-\xbf]{2} |
-          [\xf0-\xf4][\x80-\xbf]{3}
-            )+ |
-            [\x80-\xc1\xf5-\xff]       # invalid
-              )/nx) { |c|
-                c.size == 1 and raise GeneratorError, "invalid utf8 byte: '#{c}'"
-                s = PSON::UTF8toUTF16.iconv(c).unpack('H*')[0]
-                s.gsub!(/.{4}/n, '\\\\u\&')
-              }
-      string.force_encoding(Encoding::UTF_8)
       string
     rescue Iconv::Failure => e
       raise GeneratorError, "Caught #{e.class}: #{e}"
     end
   else
     def utf8_to_pson(string) # :nodoc:
-      string.
-        gsub(/["\\\x0-\x1f]/n) { MAP[$MATCH] }.
-        gsub(/((?:
-          [\xc2-\xdf][\x80-\xbf]    |
-          [\xe0-\xef][\x80-\xbf]{2} |
-          [\xf0-\xf4][\x80-\xbf]{3}
-            )+)/nx) { |c|
-        PSON::UTF8toUTF16.iconv(c).unpack('H*')[0].gsub(/.{4}/n, '\\\\u\&')
-      }
+      string.gsub(/["\\\x0-\x1f]/n) { MAP[$MATCH] }
     end
   end
   module_function :utf8_to_pson
diff --git a/spec/unit/util/pson_spec.rb b/spec/unit/util/pson_spec.rb
index d02d28517..474ddafa4 100755
--- a/spec/unit/util/pson_spec.rb
+++ b/spec/unit/util/pson_spec.rb
@@ -35,4 +35,19 @@ describe Puppet::Util::Pson do
     bin_string = (1..20000).collect { |i| ((17*i+13*i*i) % 255).chr }.join
     PSON.parse(%Q{{ "type": "foo", "data": #{bin_string.to_pson} }})["data"].should == bin_string
   end
+
+  it "should be able to handle UTF8 that isn't a real unicode character" do
+    s = ["\355\274\267"]
+    PSON.parse( [s].to_pson ).should == [s]
+  end
+
+  it "should be able to handle UTF8 for \\xFF" do
+    s = ["\xc3\xbf"]
+    PSON.parse( [s].to_pson ).should == [s]
+  end
+
+  it "should be able to handle invalid UTF8 bytes" do
+    s = ["\xc3\xc3"]
+    PSON.parse( [s].to_pson ).should == [s]
+  end
 end