Properly allow a trailing tab character on a block scalar (#919)

Fixes #917

src/scanscalar.cpp

@@ -204,7 +204,7 @@ std::string ScanScalar(Stream& INPUT, ScanScalarParams& params) {
 
   // post-processing
   if (params.trimTrailingSpaces) {
-    std::size_t pos = scalar.find_last_not_of(' ');
+    std::size_t pos = scalar.find_last_not_of(" \t");
     if (lastEscapedChar != std::string::npos) {
       if (pos < lastEscapedChar || pos == std::string::npos) {
         pos = lastEscapedChar;

test/integration/load_node_test.cpp

@@ -284,6 +284,11 @@ TEST(NodeTest, SpecialFlow) {
       {"{:a}", NodeType::Map, 1, "{:a: ~}"},
       {"{,}", NodeType::Map, 1, "{~: ~}"},
       {"{a:,}", NodeType::Map, 1, "{a: ~}"},
+      //testcase for the trailing TAB of scalar
+      {"key\t: value\t", NodeType::Map, 1, "key: value"},
+      {"key\t: value\t #comment", NodeType::Map, 1, "key: value"},
+      {"{key\t: value\t}", NodeType::Map, 1, "{key: value}"},
+      {"{key\t: value\t #comment\n}", NodeType::Map, 1, "{key: value}"},
   };
   for (const SingleNodeTestCase& test : tests) {
     Node node = Load(test.input);