Down-integrate from internal branch

python/google/protobuf/internal/text_format_test.py

diff --git a/python/google/protobuf/internal/text_format_test.py b/python/google/protobuf/internal/text_format_test.py
index 23b50eb..4b1b4f5 100755
--- a/python/google/protobuf/internal/text_format_test.py
+++ b/python/google/protobuf/internal/text_format_test.py
@@ -429,6 +429,26 @@
         ('1:17 : Couldn\'t parse integer: bork'),
         text_format.Merge, text, message)
 
+  def testMergeStringFieldUnescape(self):
+    message = unittest_pb2.TestAllTypes()
+    text = r'''repeated_string: "\xf\x62"
+               repeated_string: "\\xf\\x62"
+               repeated_string: "\\\xf\\\x62"
+               repeated_string: "\\\\xf\\\\x62"
+               repeated_string: "\\\\\xf\\\\\x62"
+               repeated_string: "\x5cx20"'''
+    text_format.Merge(text, message)
+
+    SLASH = '\\'
+    self.assertEqual('\x0fb', message.repeated_string[0])
+    self.assertEqual(SLASH + 'xf' + SLASH + 'x62', message.repeated_string[1])
+    self.assertEqual(SLASH + '\x0f' + SLASH + 'b', message.repeated_string[2])
+    self.assertEqual(SLASH + SLASH + 'xf' + SLASH + SLASH + 'x62',
+                     message.repeated_string[3])
+    self.assertEqual(SLASH + SLASH + '\x0f' + SLASH + SLASH + 'b',
+                     message.repeated_string[4])
+    self.assertEqual(SLASH + 'x20', message.repeated_string[5])
+
   def assertRaisesWithMessage(self, e_class, e, func, *args, **kwargs):
     """Same as assertRaises, but also compares the exception message."""
     if hasattr(e_class, '__name__'):

python/google/protobuf/text_format.py

diff --git a/python/google/protobuf/text_format.py b/python/google/protobuf/text_format.py
index 0714c39..24dd07f 100755
--- a/python/google/protobuf/text_format.py
+++ b/python/google/protobuf/text_format.py
@@ -608,12 +608,17 @@
   return "".join([escape(c) for c in text])
 
 
-_CUNESCAPE_HEX = re.compile('\\\\x([0-9a-fA-F]{2}|[0-9a-fA-F])')
+_CUNESCAPE_HEX = re.compile(r'(\\+)x([0-9a-fA-F])(?![0-9a-fA-F])')
 
 
 def _CUnescape(text):
   def ReplaceHex(m):
-    return chr(int(m.group(0)[2:], 16))
+    # Only replace the match if the number of leading back slashes is odd. i.e.
+    # the slash itself is not escaped.
+    if len(m.group(1)) & 1:
+      return m.group(1) + 'x0' + m.group(2)
+    return m.group(0)
+
   # This is required because the 'string_escape' encoding doesn't
   # allow single-digit hex escapes (like '\xf').
   result = _CUNESCAPE_HEX.sub(ReplaceHex, text)

src/google/protobuf/compiler/java/java_doc_comment.h

diff --git a/src/google/protobuf/compiler/java/java_doc_comment.h b/src/google/protobuf/compiler/java/java_doc_comment.h
index f77720b..7244d9b 100644
--- a/src/google/protobuf/compiler/java/java_doc_comment.h
+++ b/src/google/protobuf/compiler/java/java_doc_comment.h
@@ -59,7 +59,7 @@
                            const MethodDescriptor* method);
 
 // Exposed for testing only.
-string EscapeJavadoc(const string& input);
+LIBPROTOC_EXPORT string EscapeJavadoc(const string& input);
 
 }  // namespace java
 }  // namespace compiler

src/google/protobuf/compiler/subprocess.h

diff --git a/src/google/protobuf/compiler/subprocess.h b/src/google/protobuf/compiler/subprocess.h
index de9fce9..0056496 100644
--- a/src/google/protobuf/compiler/subprocess.h
+++ b/src/google/protobuf/compiler/subprocess.h
@@ -53,7 +53,7 @@
 namespace compiler {
 
 // Utility class for launching sub-processes.
-class Subprocess {
+class LIBPROTOC_EXPORT Subprocess {
  public:
   Subprocess();
   ~Subprocess();