Ignore the "adding children to leaf" warning for keys that are discovered in source.

lib/i18n/tasks/data/tree/node.rb

@@ -10,14 +10,17 @@ class Node # rubocop:disable Metrics/ClassLength
     attr_accessor :value
     attr_reader :key, :children, :parent
 
-    def initialize(key:, value: nil, data: nil, parent: nil, children: nil)
+    # rubocop:disable Metrics/ParameterLists
+    def initialize(key:, value: nil, data: nil, parent: nil, children: nil, warn_about_add_children_to_leaf: true)
       @key = key
       @key = @key.to_s.freeze if @key
       @value = value
       @data = data
       @parent = parent
+      @warn_about_add_children_to_leaf = warn_about_add_children_to_leaf
       self.children = (children if children)
     end
+    # rubocop:enable Metrics/ParameterLists
 
     def attributes
       { key: @key, value: @value, data: @data.try(:clone), parent: @parent, children: @children }
@@ -34,7 +37,11 @@ def children=(children)
                   when NilClass
                     nil
                   else
-                    Siblings.new(nodes: children, parent: self)
+                    Siblings.new(
+                      nodes: children,
+                      parent: self,
+                      warn_about_add_children_to_leaf: @warn_about_add_children_to_leaf
+                    )
                   end
       dirty!
     end

lib/i18n/tasks/data/tree/siblings.rb

@@ -18,6 +18,7 @@ def initialize(opts = {})
       @parent = opts[:parent] || first.try(:parent)
       @list.map! { |node| node.parent == @parent ? node : node.derive(parent: @parent) }
       @key_to_node = @list.each_with_object({}) { |node, h| h[node.key] = node }
+      @warn_about_add_children_to_leaf = opts.fetch(:warn_about_add_children_to_leaf, true)
     end
 
     def attributes
@@ -104,11 +105,16 @@ def set(full_key, node)
 
       if rest
         unless child
-          child = Node.new(key: key_part, parent: parent, children: [])
+          child = Node.new(
+            key: key_part,
+            parent: parent,
+            children: [],
+            warn_about_add_children_to_leaf: @warn_add_children_to_leaf
+          )
           append! child
         end
         unless child.children
-          warn_add_children_to_leaf child
+          warn_add_children_to_leaf child if @warn_about_add_children_to_leaf
           child.children = []
         end
         child.children.set rest, node
@@ -254,7 +260,7 @@ def build_forest(opts = {}, &block)
       # @param key_occurrences [I18n::Tasks::Scanners::KeyOccurrences]
       # @return [Siblings]
       def from_key_occurrences(key_occurrences)
-        build_forest do |forest|
+        build_forest(warn_about_add_children_to_leaf: false) do |forest|
           key_occurrences.each do |key_occurrence|
             forest[key_occurrence.key] = ::I18n::Tasks::Data::Tree::Node.new(
               key:  split_key(key_occurrence.key).last,

spec/used_keys_spec.rb

@@ -9,6 +9,8 @@
 div = t 'a'
   p = t 'a'
 h1 = t 'b'
+h2 = t 'c.layer'
+h3 = t 'c.layer.underneath_c'
     SLIM
   end
 
@@ -20,9 +22,11 @@
   end
 
   it '#used_keys' do
+    allow(I18n::Tasks::Logging).to receive(:log_warn).exactly(0).times
+
     used   = task.used_tree
     leaves = used.leaves.to_a
-    expect(leaves.size).to eq 2
+    expect(leaves.size).to eq 3
     expect_node_key_data(
       leaves[0],
       'a',
@@ -42,6 +46,8 @@
   end
 
   it '#used_keys(key_filter: "b*")' do
+    allow(I18n::Tasks::Logging).to receive(:log_warn).exactly(0).times
+
     used_keys = task.used_tree(key_filter: 'b*')
     expect(used_keys.size).to eq 1
     expect_node_key_data(