indents(cpp): indent at field_initializer_list

lua/nvim-treesitter/indent.lua

@@ -117,7 +117,7 @@ function M.get_indent(lnum)
     end
 
     -- do not indent for nodes that starts-and-ends on same line and starts on target line (lnum)
-    if not is_processed_by_row[srow] and (q.indent[node:id()] and srow ~= erow and srow ~= lnum - 1) then
+    if not is_processed_by_row[srow] and (q.indent[node:id()] and srow ~= erow and ((srow ~= lnum - 1) or q.indent[node:id()].start_at_same_line)) then
       indent = indent + indent_size
       is_processed = true
     end

queries/cpp/indents.scm

@@ -5,4 +5,6 @@
   (condition_clause)
 ] @indent
 
+((field_initializer_list) @indent
+  (#set! "start_at_same_line" 1))
 (access_specifier) @branch

tests/indent/cpp/initializer_list.cpp

@@ -0,0 +1,17 @@
+class Foo {
+
+  Foo(int a, int b, int c, int d)
+    : m_a(a)
+    , m_b(b)
+    , m_c(c)
+    , m_d(d) {}
+
+  Foo(int a, int b, int c) :
+    m_a(a),
+    m_b(b),
+    m_c(c)
+  {}
+
+  int m_a, m_b, m_c, m_d;
+};
+