RST reader: Use a new one-pass parsing strategy.

Instead of having an initial pass where we collect reference
definitions, we create links with target `##SUBST##something`
or `##REF##something` or `##NOTE##something`, and resolve these
in a pass over the parsed AST.

This allows us to handle link references that are not at the
top level. Closes #10281.

2 files changed, 69 insertions, 1 deletions

diff --git a/test/command/10281.md b/test/command/10281.md
new file mode 100644
index 000000000..a946061e7
--- /dev/null
+++ b/test/command/10281.md
@@ -0,0 +1,68 @@
+```
+% pandoc -f rst -t native
+`Want Speed? Pass by Value`_
+
+.. note::
+  For more information about the pass-by-value idiom, read: `Want Speed? Pass by Value`_.
+
+  .. _Want Speed? Pass by Value: https://web.archive.org/web/20140205194657/http://cpp-next.com/archive/2009/08/want-speed-pass-by-value/
+^D
+[ Para
+    [ Link
+        ( "" , [] , [] )
+        [ Str "Want"
+        , Space
+        , Str "Speed?"
+        , Space
+        , Str "Pass"
+        , Space
+        , Str "by"
+        , Space
+        , Str "Value"
+        ]
+        ( "https://web.archive.org/web/20140205194657/http://cpp-next.com/archive/2009/08/want-speed-pass-by-value/"
+        , ""
+        )
+    ]
+, Div
+    ( "" , [ "note" ] , [] )
+    [ Div ( "" , [ "title" ] , [] ) [ Para [ Str "Note" ] ]
+    , Para
+        [ Str "For"
+        , Space
+        , Str "more"
+        , Space
+        , Str "information"
+        , Space
+        , Str "about"
+        , Space
+        , Str "the"
+        , Space
+        , Str "pass-by-value"
+        , Space
+        , Str "idiom,"
+        , Space
+        , Str "read:"
+        , Space
+        , Link
+            ( "" , [] , [] )
+            [ Str "Want"
+            , Space
+            , Str "Speed?"
+            , Space
+            , Str "Pass"
+            , Space
+            , Str "by"
+            , Space
+            , Str "Value"
+            ]
+            ( "https://web.archive.org/web/20140205194657/http://cpp-next.com/archive/2009/08/want-speed-pass-by-value/"
+            , ""
+            )
+        , Str "."
+        ]
+    ]
+]
+
+```
+
diff --git a/test/command/512.md b/test/command/512.md
index 20053d9cd..48f1f101a 100644
--- a/test/command/512.md
+++ b/test/command/512.md
@@ -37,7 +37,7 @@ Loop detection:
 
 __ link1_
 ^D
-2> [WARNING] Circular reference 'link1' at line 1 column 15
+2> [WARNING] Circular reference 'link1' at line 8 column 1
 <p><a href="">click here</a></p>
 ```