From 10b7bbcc29d442da41f0d3612895b7de2e57a152 Mon Sep 17 00:00:00 2001
From: Joao Paulo Magalhaes <dev@jpmag.me>
Date: Thu, 8 Aug 2024 10:20:07 +0200
Subject: [PATCH] fix parsing of val-less nested maps when deindented to maps

re #455
---
 changelog/current.md            |  1 +
 src/c4/yml/parse_engine.def.hpp |  6 ++++
 test/test_github_issues.cpp     | 61 +++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)

diff --git a/changelog/current.md b/changelog/current.md
index c8327e9e..08c4eb7e 100644
--- a/changelog/current.md
+++ b/changelog/current.md
@@ -1,5 +1,6 @@
 ## Fixes
 
+- Fix [#455](https://github.com/biojppm/rapidyaml/issues/455): parsing of trailing val-less nested maps when deindented to maps ([PR#460](https://github.com/biojppm/rapidyaml/pull/460))
 - Fix filtering of double-quoted keys in block maps ([PR#452](https://github.com/biojppm/rapidyaml/pull/452))
 - Fix [#440](https://github.com/biojppm/rapidyaml/issues/440): some tests failing with gcc -O2 (hypothetically due to undefined behavior)
   - This was accomplished by refactoring some internal parser functions; see the comments in [#440](https://github.com/biojppm/rapidyaml/issues/440) for further details.
diff --git a/src/c4/yml/parse_engine.def.hpp b/src/c4/yml/parse_engine.def.hpp
index 458b6c85..4e46040a 100644
--- a/src/c4/yml/parse_engine.def.hpp
+++ b/src/c4/yml/parse_engine.def.hpp
@@ -6338,6 +6338,12 @@ void ParseEngine<EventHandler>::_handle_map_block()
                 {
                     _c4dbgp("mapblck[RVAL]: still mapblck!");
                     _line_progressed(m_evt_handler->m_curr->line_contents.indentation);
+                    if(has_any(RNXT))
+                    {
+                        _c4dbgp("mapblck[RVAL]: speculatively expect next keyval");
+                        m_evt_handler->add_sibling();
+                        addrem_flags(RKEY, RNXT);
+                    }
                     goto mapblck_again;
                 }
                 else
diff --git a/test/test_github_issues.cpp b/test/test_github_issues.cpp
index 6d44f0e3..bad0eee4 100644
--- a/test/test_github_issues.cpp
+++ b/test/test_github_issues.cpp
@@ -4,6 +4,67 @@
 namespace c4 {
 namespace yml {
 
+TEST(github, 455_0_ok)
+{
+    Tree t;
+    ExpectError::check_success([&t]{
+        parse_in_arena(R"(
+  processors:
+    - simple: a
+  sampler:
+    trace_id_ratio_based:
+      ratio:
+)", &t);
+    });
+    ConstNodeRef sampler = t["sampler"];
+    ASSERT_TRUE(sampler.is_map());
+    ASSERT_TRUE(sampler.has_child("trace_id_ratio_based"));
+    ASSERT_TRUE(sampler["trace_id_ratio_based"].has_child("ratio"));
+}
+
+TEST(github, 455_0)
+{
+    Tree t;
+    ExpectError::check_success([&t]{
+        parse_in_arena(R"(
+  processors:
+    - simple:
+  sampler:
+    trace_id_ratio_based:
+      ratio:
+)", &t);
+    });
+    ConstNodeRef sampler = t["sampler"];
+    ASSERT_TRUE(sampler.is_map());
+    ASSERT_TRUE(sampler.has_child("trace_id_ratio_based"));
+    ASSERT_TRUE(sampler["trace_id_ratio_based"].has_child("ratio"));
+}
+
+TEST(github, 455_1)
+{
+    Tree t;
+    ExpectError::check_success([&t]{
+        parse_in_arena(R"(
+file_format: 0.0
+tracer_provider:
+  processors:
+    - simple:
+        exporter:
+          console:
+  sampler:
+    trace_id_ratio_based:
+      ratio:
+    )", &t);
+    });
+    ConstNodeRef sampler = t["tracer_provider"]["sampler"];
+    ASSERT_TRUE(sampler.is_map());
+    ASSERT_TRUE(sampler.has_child("trace_id_ratio_based"));
+    ASSERT_TRUE(sampler["trace_id_ratio_based"].has_child("ratio"));
+}
+
+
+//-----------------------------------------------------------------------------
+
 TEST(github, 268)
 {
     Tree tree = parse_in_arena(R"(