Fix bug on tags starting with "!!"

src/emitfromevents.cpp

@@ -117,16 +117,26 @@ void EmitFromEvents::BeginNode() {
 
 void EmitFromEvents::EmitProps(const std::string& tag, anchor_t anchor) {
   if (!tag.empty() && tag != "?" && tag != "!"){
-      if (tag.size() >= 2 && tag[0] == '!' && tag[1] == '!') {
-        // Tags like "!!str" use the secondary tag handle; emit them through
-        // SecondaryTag so the rendered output keeps both bangs instead of
-        // failing the LocalTag regex check on the inner '!'. See #1373.
-        m_emitter << SecondaryTag(std::string(tag.begin()+2, tag.end()));
-      } else if (tag[0] == '!') {
-        m_emitter << LocalTag(std::string(tag.begin()+1, tag.end()));
-      } else {
-        m_emitter << VerbatimTag(tag);
+    if (tag.size() >= 2 && tag[0] == '!' && tag[1] == '!') {
+      // Tags like "!!str" use the secondary tag handle; emit them through
+      // SecondaryTag so the rendered output keeps both bangs instead of
+      // failing the LocalTag regex check on the inner '!'. See #1373.
+      m_emitter << SecondaryTag(std::string(tag.begin()+2, tag.end()));
+    } else if (tag[0] == '!') {
+      auto prefix_end = tag.begin() + 1;
+      while (prefix_end != tag.end() && *prefix_end != '!') {
+        ++prefix_end;
       }
+      if (prefix_end == tag.end()) {
+        m_emitter << LocalTag(std::string(tag.begin() + 1, tag.end()));
+      }
+      else {
+        m_emitter << LocalTag(std::string(tag.begin() + 1, prefix_end),
+                                std::string(prefix_end + 1, tag.end()));
+      }
+    } else {
+      m_emitter << VerbatimTag(tag);
+    }
   }
   if (anchor)
     m_emitter << Anchor(ToString(anchor));

test/integration/load_node_test.cpp

@@ -231,6 +231,17 @@ TEST(NodeTest, EmitEmptyNode) {
   EXPECT_EQ("", std::string(emitter.c_str()));
 }
 
+TEST(NodeTest, SetVerbatimTag) {
+  Node node, root;
+  node = 42;
+  node.SetTag("hello");
+  root["num"] = node;
+
+  Emitter emitter;
+  emitter << root;
+  EXPECT_EQ("num: !<hello> 42", std::string(emitter.c_str()));
+}
+
 // Regression for #1373: emitting a node whose tag begins with "!!"
 // (a YAML secondary tag handle, e.g. "!!str") used to bail out with
 // INVALID_TAG and truncate the output after the first '!'.
@@ -258,6 +269,17 @@ TEST(NodeTest, EmitSetTagPrimaryHandle) {
   EXPECT_EQ("v: !mytag hello", std::string(emitter.c_str()));
 }
 
+TEST(NodeTest, EmitSetLocalTagInNameHandle) {
+  Node node, root;
+  node = 42;
+  node.SetTag("!a!foo");
+  root["num"] = node;
+
+  Emitter emitter;
+  emitter << root;
+  EXPECT_EQ("num: !a!foo 42", std::string(emitter.c_str()));
+}
+
 TEST(NodeTest, ParseNodeStyle) {
   EXPECT_EQ(EmitterStyle::Flow, Load("[1, 2, 3]").Style());
   EXPECT_EQ(EmitterStyle::Flow, Load("{foo: bar}").Style());
@@ -497,4 +519,4 @@ TEST(LoadNodeTest, NonUniqueMapKey) {
 }
 
 }  // namespace
-}  // namespace YAML
+}  // namespace YAML