fix(parser): Failed on mixed inline tables

crates/toml/tests/decoder_compliance.rs

@@ -4,12 +4,7 @@ mod decoder;
 fn main() {
     let decoder = decoder::Decoder;
     let mut harness = toml_test_harness::DecoderHarness::new(decoder);
-    harness
-        .ignore([
-            "valid/spec/float-0.toml",
-            "invalid/inline-table/nested_key_conflict.toml",
-        ])
-        .unwrap();
+    harness.ignore(["valid/spec/float-0.toml"]).unwrap();
     harness.version("1.0.0");
     harness.test();
 }

crates/toml_edit/src/inline_table.rs

@@ -11,6 +11,8 @@ use crate::{InternalString, Item, KeyMut, RawString, Table, Value};
 pub struct InlineTable {
     // `preamble` represents whitespaces in an empty table
     preamble: RawString,
+    // Whether to hide an empty table
+    pub(crate) implicit: bool,
     // prefix before `{` and suffix after `}`
     decor: Decor,
     pub(crate) span: Option<std::ops::Range<usize>>,
@@ -133,6 +135,32 @@ impl InlineTable {
         }
     }
 
+    /// If a table has no key/value pairs and implicit, it will not be displayed.
+    ///
+    /// # Examples
+    ///
+    /// ```notrust
+    /// [target."x86_64/windows.json".dependencies]
+    /// ```
+    ///
+    /// In the document above, tables `target` and `target."x86_64/windows.json"` are implicit.
+    ///
+    /// ```
+    /// use toml_edit::Document;
+    /// let mut doc = "[a]\n[a.b]\n".parse::<Document>().expect("invalid toml");
+    ///
+    /// doc["a"].as_table_mut().unwrap().set_implicit(true);
+    /// assert_eq!(doc.to_string(), "[a.b]\n");
+    /// ```
+    pub(crate) fn set_implicit(&mut self, implicit: bool) {
+        self.implicit = implicit;
+    }
+
+    /// If a table has no key/value pairs and implicit, it will not be displayed.
+    pub(crate) fn is_implicit(&self) -> bool {
+        self.implicit
+    }
+
     /// Change this table's dotted status
     pub fn set_dotted(&mut self, yes: bool) {
         self.dotted = yes;

crates/toml_edit/src/parser/inline_table.rs

@@ -44,6 +44,16 @@ fn table_from_pairs(
 
     for (path, kv) in v {
         let table = descend_path(&mut root, &path)?;
+
+        // "Likewise, using dotted keys to redefine tables already defined in [table] form is not allowed"
+        let mixed_table_types = table.is_dotted() == path.is_empty();
+        if mixed_table_types {
+            return Err(CustomError::DuplicateKey {
+                key: kv.key.get().into(),
+                table: None,
+            });
+        }
+
         let key: InternalString = kv.key.get_internal().into();
         match table.items.entry(key) {
             Entry::Vacant(o) => {
@@ -64,15 +74,26 @@ fn descend_path<'a>(
     mut table: &'a mut InlineTable,
     path: &'a [Key],
 ) -> Result<&'a mut InlineTable, CustomError> {
+    let dotted = !path.is_empty();
     for (i, key) in path.iter().enumerate() {
         let entry = table.entry_format(key).or_insert_with(|| {
             let mut new_table = InlineTable::new();
-            new_table.set_dotted(true);
+            new_table.set_implicit(dotted);
+            new_table.set_dotted(dotted);
 
             Value::InlineTable(new_table)
         });
         match *entry {
             Value::InlineTable(ref mut sweet_child_of_mine) => {
+                // Since tables cannot be defined more than once, redefining such tables using a
+                // [table] header is not allowed. Likewise, using dotted keys to redefine tables
+                // already defined in [table] form is not allowed.
+                if dotted && !sweet_child_of_mine.is_implicit() {
+                    return Err(CustomError::DuplicateKey {
+                        key: key.get().into(),
+                        table: None,
+                    });
+                }
                 table = sweet_child_of_mine;
             }
             ref v => {

crates/toml_edit/tests/decoder_compliance.rs

@@ -3,12 +3,7 @@ mod decoder;
 fn main() {
     let decoder = decoder::Decoder;
     let mut harness = toml_test_harness::DecoderHarness::new(decoder);
-    harness
-        .ignore([
-            "valid/spec/float-0.toml",
-            "invalid/inline-table/nested_key_conflict.toml",
-        ])
-        .unwrap();
+    harness.ignore(["valid/spec/float-0.toml"]).unwrap();
     harness.version("1.0.0");
     harness.test();
 }

crates/toml_edit/tests/fixtures/invalid/inline-table/nested_key_conflict.stderr

@@ -0,0 +1,5 @@
+TOML parse error at line 1, column 8
+  |
+1 | tbl = { fruit = { apple.color = "red" }, fruit.apple.texture = { smooth = true } }
+  |        ^
+duplicate key `fruit`