Fix continuing first line of explicit [/{ literal (#5397)

docs/v2/test.html

@@ -30853,6 +30853,42 @@ <h2>Another heading</h2>
   eq 2, a.b.d
   eq 3, a.e
 
+test "#5368: continuing object and array literals", ->
+  { a
+    b: { c }
+  } = {a: 1, b: {c: 2}}
+  eq a, 1
+  eq c, 2
+
+  [d
+   e: f
+  ] = [3, {e: 4}]
+  eq d, 3
+  eq f, 4
+  A =
+    [d
+     e: f
+    ]
+  eq A[0], 3
+  eq A[1].e, 4
+
+  for obj in [
+    {a: a
+     c: c
+    }
+    {a: a
+     c
+    }
+    {a
+     c: c
+    }
+    {a
+     c
+    }
+  ]
+    eq obj.a, 1
+    eq obj.c, 2
+
 </script>
 <script type="text/x-coffeescript" class="test" id="operators">
 # Operators

src/rewriter.coffee

@@ -314,12 +314,15 @@ exports.Rewriter = class Rewriter
       #     if f(a: 1)
       #
       # which is probably always unintended.
-      # Furthermore don’t allow this in literal arrays, as
-      # that creates grammatical ambiguities.
+      # Furthermore don’t allow this in the first line of a literal array
+      # or explicit object, as that creates grammatical ambiguities (#5368).
       if tag in IMPLICIT_FUNC and
          @indexOfTag(i + 1, 'INDENT') > -1 and @looksObjectish(i + 2) and
          not @findTagsBackwards(i, ['CLASS', 'EXTENDS', 'IF', 'CATCH',
-          'SWITCH', 'LEADING_WHEN', 'FOR', 'WHILE', 'UNTIL'])
+          'SWITCH', 'LEADING_WHEN', 'FOR', 'WHILE', 'UNTIL']) and
+         not ((s = stackTop()?[0]) in ['{', '['] and
+              not isImplicit(stackTop()) and
+              @findTagsBackwards(i, s))
         startImplicitCall i + 1
         stack.push ['INDENT', i + 2]
         return forward(3)
@@ -339,9 +342,14 @@ exports.Rewriter = class Rewriter
 
         startsLine = s <= 0 or @tag(s - 1) in LINEBREAKS or tokens[s - 1].newLine
         # Are we just continuing an already declared object?
+        # Including the case where we indent on the line after an explicit '{'.
         if stackTop()
           [stackTag, stackIdx] = stackTop()
-          if (stackTag is '{' or stackTag is 'INDENT' and @tag(stackIdx - 1) is '{') and
+          stackNext = stack[stack.length - 2]
+          if (stackTag is '{' or
+              stackTag is 'INDENT' and stackNext?[0] is '{' and
+              not isImplicit(stackNext) and
+              @findTagsBackwards(stackIdx-1, ['{'])) and
              (startsLine or @tag(s - 1) is ',' or @tag(s - 1) is '{') and
              @tag(s - 1) not in UNFINISHED
             return forward(1)

test/objects.coffee

@@ -930,3 +930,39 @@ test "#5292: implicit object after line continuer in implicit object property va
   eq 1, a.b.c
   eq 2, a.b.d
   eq 3, a.e
+
+test "#5368: continuing object and array literals", ->
+  { a
+    b: { c }
+  } = {a: 1, b: {c: 2}}
+  eq a, 1
+  eq c, 2
+
+  [d
+   e: f
+  ] = [3, {e: 4}]
+  eq d, 3
+  eq f, 4
+  A =
+    [d
+     e: f
+    ]
+  eq A[0], 3
+  eq A[1].e, 4
+
+  for obj in [
+    {a: a
+     c: c
+    }
+    {a: a
+     c
+    }
+    {a
+     c: c
+    }
+    {a
+     c
+    }
+  ]
+    eq obj.a, 1
+    eq obj.c, 2