Always format zero as hex with a leading 0x

The standard library's `std::setbase` specifies special behaviour for zero (no
leading `0x`). Clang doesn't follow the standard, but GCC does.

This change avoids both the problem of unexpected (but standards-compliant)
output with GCC and the inconsistency between the two toolchains.

PiperOrigin-RevId: 604344160
Change-Id: I320fd033f291b887e53ee4dc2723615458da0f3e

2 files changed, 2 insertions, 3 deletions

diff --git a/error.h b/error.h
index 5ca6c57..b72faaf 100644
--- a/error.h
+++ b/error.h
@@ -124,7 +124,7 @@ template <typename T>
 std::ostream& operator<<(std::ostream& os, const Hex<T>& hex_value) {
   // not quite right if an exception is thrown
   const auto flags = os.flags();
-  os << std::hex << std::showbase << hex_value.value;
+  os << "0x" << std::hex << hex_value.value;
   os.flags(flags);
   return os;
 }
diff --git a/proto_writer.cc b/proto_writer.cc
index 122872a..d3de03d 100644
--- a/proto_writer.cc
+++ b/proto_writer.cc
@@ -497,8 +497,7 @@ class HexPrinter : public google::protobuf::TextFormat::FastFieldValuePrinter {
       google::protobuf::TextFormat::BaseTextGenerator* generator) const override {
     std::ostringstream os;
     // 0x01234567
-    os << std::showbase << std::hex << std::setfill('0') << std::internal
-       << std::setw(10) << value;
+    os << "0x" << std::hex << std::setfill('0') << std::setw(8) << value;
     generator->PrintString(os.str());
   }
 };