Disable canceled step/next/finish

When `next` command canceled with other breaks, for example, stop
at a breakpoint while executing `next` command, the `next` command
should be canceled and it should not stop on the next line.

However, the current implementation left the TracePoint object for
step commands, so it should be disabled.

lib/debug/session.rb

@@ -89,7 +89,7 @@ module DEBUGGER__
   class PostmortemError < RuntimeError; end
 
   class Session
-    attr_reader :intercepted_sigint_cmd, :process_group
+    attr_reader :intercepted_sigint_cmd, :process_group, :subsession_id
 
     include Color
 
@@ -116,6 +116,7 @@ def initialize
       @intercepted_sigint_cmd = 'DEFAULT'
       @process_group = ProcessGroup.new
       @subsession_stack = []
+      @subsession_id = 0
 
       @frame_map = {} # for DAP: {id => [threadId, frame_depth]} and CDP: {id => frame_depth}
       @var_map   = {1 => [:globals], } # {id => ...} for DAP
@@ -138,8 +139,14 @@ def active?
       !@q_evt.closed?
     end
 
-    def break_at? file, line
-      @bps.has_key? [file, line]
+    def stop_stepping? file, line, subsession_id
+      if @bps.has_key? [file, line]
+        true
+      elsif @subsession_id != subsession_id
+        true
+      else
+        false
+      end
     end
 
     def activate ui = nil, on_fork: false
@@ -1571,6 +1578,7 @@ def get_thread_client th = Thread.current
     end
 
     private def enter_subsession
+      @subsession_id += 1
       if !@subsession_stack.empty?
         DEBUGGER__.info "Enter subsession (nested #{@subsession_stack.size})"
       else

lib/debug/thread_client.rb

@@ -328,10 +328,14 @@ def step_tp iter, events = [:line, :b_return, :return]
       @step_tp.disable if @step_tp
 
       thread = Thread.current
+      subsession_id = SESSION.subsession_id
 
       if SUPPORT_TARGET_THREAD
         @step_tp = TracePoint.new(*events){|tp|
-          next if SESSION.break_at? tp.path, tp.lineno
+          if SESSION.stop_stepping? tp.path, tp.lineno, subsession_id
+            tp.disable
+            next
+          end
           next if !yield(tp.event)
           next if tp.path.start_with?(__dir__)
           next if tp.path.start_with?('<internal:trace_point>')
@@ -347,7 +351,10 @@ def step_tp iter, events = [:line, :b_return, :return]
       else
         @step_tp = TracePoint.new(*events){|tp|
           next if thread != Thread.current
-          next if SESSION.break_at? tp.path, tp.lineno
+          if SESSION.stop_stepping? tp.path, tp.lineno, subsession_id
+            tp.disable
+            next
+          end
           next if !yield(tp.event)
           next if tp.path.start_with?(__dir__)
           next if tp.path.start_with?('<internal:trace_point>')

test/console/control_flow_commands_test.rb

@@ -358,4 +358,50 @@ def test_next_steps_over_rescue_when_raising_from_method
       end
     end
   end
+
+  class CancelStepTest < ConsoleTestCase
+    def program
+      <<~RUBY
+       1| def foo m
+       2|  __send__ m
+       3| end
+       4| def bar
+       5|   a = :bar1
+       6|   b = :bar2
+       7|   c = :bar3
+       8| end
+       9|
+      10| def baz
+      11|   :baz
+      12| end
+      13| foo :bar
+      14| foo :baz
+      15| foo :baz
+      RUBY
+    end
+
+    def test_next_should_be_canceled
+      debug_code program do
+        type 'b 13'
+        type 'b Object#bar'
+        type 'c'
+        assert_line_num 13
+        type 'n'
+        assert_line_num 5
+        type 'c'
+      end
+    end
+
+    def test_finish_should_be_canceled
+      debug_code program do
+        type 'b 5'
+        type 'b 6'
+        type 'c'
+        assert_line_num 5
+        type 'finish'
+        assert_line_num 6
+        type 'c'
+      end
+    end
+  end
 end