HPUX patch from Alexander Melnikov.
diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index f9f2a6a..d2c3d18 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -72,3 +72,5 @@
     * Emacs mode for Protocol Buffers (editors/protobuf-mode.el).
   Scott Stafford <scott.stafford@gmail.com>
     * Added Swap(), SwapElements(), and RemoveLast() to Reflection interface.
+  Alexander Melnikov <alm@sibmail.ru>
+    * HPUX support.
diff --git a/src/google/protobuf/compiler/importer.cc b/src/google/protobuf/compiler/importer.cc
index 8a07dfc..7689ce9 100644
--- a/src/google/protobuf/compiler/importer.cc
+++ b/src/google/protobuf/compiler/importer.cc
@@ -59,6 +59,7 @@
 #ifndef F_OK
 #define F_OK 00  // not defined by MSVC for whatever reason
 #endif
+#include <ctype.h>
 #endif
 
 // Returns true if the text looks like a Windows-style absolute path, starting
diff --git a/src/google/protobuf/io/zero_copy_stream_unittest.cc b/src/google/protobuf/io/zero_copy_stream_unittest.cc
index c8f669a..f919b7a 100644
--- a/src/google/protobuf/io/zero_copy_stream_unittest.cc
+++ b/src/google/protobuf/io/zero_copy_stream_unittest.cc
@@ -520,7 +520,7 @@
 // these debug assertions while in scope.
 class MsvcDebugDisabler {
  public:
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && _MSC_VER >= 1400
   MsvcDebugDisabler() {
     old_handler_ = _set_invalid_parameter_handler(MyHandler);
     old_mode_ = _CrtSetReportMode(_CRT_ASSERT, 0);
diff --git a/src/google/protobuf/stubs/hash.h b/src/google/protobuf/stubs/hash.h
index c341413..a828a9c 100644
--- a/src/google/protobuf/stubs/hash.h
+++ b/src/google/protobuf/stubs/hash.h
@@ -98,7 +98,7 @@
 class hash_set : public std::set<Key, HashFcn> {
 };
 
-#elif defined(_MSC_VER)
+#elif defined(_MSC_VER) && !defined(_STLPORT_VERSION)
 
 template <typename Key>
 struct hash : public HASH_NAMESPACE::hash_compare<Key> {
diff --git a/src/google/protobuf/stubs/strutil.cc b/src/google/protobuf/stubs/strutil.cc
index a476475..32b0f03 100644
--- a/src/google/protobuf/stubs/strutil.cc
+++ b/src/google/protobuf/stubs/strutil.cc
@@ -1027,7 +1027,7 @@
 bool safe_strtof(const char* str, float* value) {
   char* endptr;
   errno = 0;  // errno only gets set on errors
-#ifdef _WIN32  // has no strtof()
+#if defined(_WIN32) || defined (__hpux)  // has no strtof()
   *value = strtod(str, &endptr);
 #else
   *value = strtof(str, &endptr);
diff --git a/src/google/protobuf/stubs/strutil.h b/src/google/protobuf/stubs/strutil.h
index 7f6bd96..c04c123 100644
--- a/src/google/protobuf/stubs/strutil.h
+++ b/src/google/protobuf/stubs/strutil.h
@@ -33,6 +33,7 @@
 #ifndef GOOGLE_PROTOBUF_STUBS_STRUTIL_H__
 #define GOOGLE_PROTOBUF_STUBS_STRUTIL_H__
 
+#include <stdlib.h>
 #include <vector>
 #include <google/protobuf/stubs/common.h>
 
diff --git a/src/google/protobuf/testing/googletest.cc b/src/google/protobuf/testing/googletest.cc
index 1339b33..cd094d0 100644
--- a/src/google/protobuf/testing/googletest.cc
+++ b/src/google/protobuf/testing/googletest.cc
@@ -46,6 +46,8 @@
 #endif
 #include <stdio.h>
 #include <fcntl.h>
+#include <iostream>
+#include <fstream>
 
 namespace google {
 namespace protobuf {
@@ -94,7 +96,8 @@
   // tmpnam() is generally not considered safe but we're only using it for
   // testing.  We cannot use tmpfile() or mkstemp() since we're creating a
   // directory.
-  string result = tmpnam(NULL);
+  char b[L_tmpnam + 1];     // HPUX multithread return 0 if s is 0
+  string result = tmpnam(b);
 #ifdef _WIN32
   // On Win32, tmpnam() returns a file prefixed with '\', but which is supposed
   // to be used in the current working directory.  WTF?