commit 3bf5bf99334c2da212e5e3d14145a1783657877c
author tpcwang <tpc.wang@gmail.com> Wed Mar 23 15:22:33 2016 -0700
committer Nobuaki Sukegawa <nsuke@apache.org> Tue Mar 29 12:03:34 2016 +0900
tree ae9f52d88824714b5921174262f5f3106866a6c8
parent 6657b8337d1aedfd2aed22a8cdcf4b96965ece26

THRIFT-3755 TDebugProtocol::writeString hits assert in isprint on Windows with debug CRT

This closes #960

lib/cpp/src/thrift/protocol/TDebugProtocol.cpp

diff --git a/lib/cpp/src/thrift/protocol/TDebugProtocol.cpp b/lib/cpp/src/thrift/protocol/TDebugProtocol.cpp
index 4687e82..09b978c 100644
--- a/lib/cpp/src/thrift/protocol/TDebugProtocol.cpp
+++ b/lib/cpp/src/thrift/protocol/TDebugProtocol.cpp
@@ -347,7 +347,9 @@
       output += "\\\\";
     } else if (*it == '"') {
       output += "\\\"";
-    } else if (std::isprint(*it)) {
+      // passing characters <0 to std::isprint causes asserts. isprint takes an
+      // int, so we need to be careful of sign extension
+    } else if (std::isprint((unsigned char)*it)) {
       output += *it;
     } else {
       switch (*it) {