GH-48478: [Ruby] Fix Ruby list inference for nested non-negative integer arrays

ruby/red-arrow/lib/arrow/array-builder.rb

@@ -155,12 +155,14 @@ def detect_builder_info(value, builder_info)
             sub_builder_info = detect_builder_info(sub_value, sub_builder_info)
             break if sub_builder_info and sub_builder_info[:detected]
           end
-          if sub_builder_info and sub_builder_info[:detected]
-            sub_value_data_type = sub_builder_info[:builder].value_data_type
+          if sub_builder_info
+            sub_builder = sub_builder_info[:builder]
+            return builder_info unless sub_builder
+            sub_value_data_type = sub_builder.value_data_type
             field = Field.new("item", sub_value_data_type)
             {
               builder: ListArrayBuilder.new(ListDataType.new(field)),
-              detected: true,
+              detected: !!sub_builder_info[:detected],
             }
           else
             builder_info

ruby/red-arrow/test/test-table.rb

@@ -72,6 +72,18 @@ def array_like.to_ary
       assert_equal(Arrow::Table.new(schema, [Arrow::UInt8Array.new([1, 2, 3])]),
                    Arrow::Table.new(numbers: array_like))
     end
+
+    test("{Symbol: nested non-negative integer Array}") do
+      table = Arrow::Table.new(numbers: [[0, 1, 2], [3, 4]])
+      assert_equal("list<item: uint8>",
+                   table.schema["numbers"].data_type.to_s)
+    end
+
+    test("{Symbol: nested signed integer Array}") do
+      table = Arrow::Table.new(numbers: [[0, -1, 2], [3, 4]])
+      assert_equal("list<item: int8>",
+                   table.schema["numbers"].data_type.to_s)
+    end
   end
 
   test("#columns") do