[clang-format] Correct indentation for `[key] = value,` entries in C# object initialisers

Restores content of commit cb3f20d27c
reverted in commit 5a101f3773
with a corrected commit message.

Summary: Do not use continuation indent for '[' in blocks in C# code.

Reviewers: krasimir

Reviewed By: krasimir

Subscribers: cfe-commits

Tags: #clang-format, #clang

Differential Revision: https://reviews.llvm.org/D75747

clang/lib/Format/ContinuationIndenter.cpp

@@ -1047,6 +1047,9 @@ unsigned ContinuationIndenter::getNewLineColumn(const LineState &State) {
   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
     if (State.Stack.back().StartOfArraySubscripts != 0)
       return State.Stack.back().StartOfArraySubscripts;
+    else if (Style.isCSharp()) // C# allows `["key"] = value` inside object
+                               // initializers.
+      return State.Stack.back().Indent;
     return ContinuationIndent;
   }
 

clang/unittests/Format/FormatTestCSharp.cpp

@@ -549,6 +549,15 @@ Shape[] shapes = new[] { new Circle { Radius = 2.7281, Colour = Colours.Red },
 private Transformer _transformer = new X.Y {
   Filler = (Shape shape) => { return new Transform.Fill(shape, RED); },
   Scaler = (Shape shape) => { return new Transform.Resize(shape, 0.1); },
+};)",
+               Style);
+
+  // Dictionary initialisation.
+  verifyFormat(R"(//
+var myDict = new Dictionary<string, string> {
+  ["name"] = _donald,
+  ["age"] = Convert.ToString(DateTime.Today.Year - 1934),
+  ["type"] = _duck,
 };)",
                Style);
 }