support reloaded breakpoints

When 'foo.rb' is reloaded, then already set breakponts on 'foo.rb'
is also enabled on reloaded 'foo.rb'.

Note that this is only for the line breakpoints.

fix #662

Author: ko1

lib/debug/breakpoint.rb

@@ -131,9 +131,17 @@ def enable
   end
 
   class LineBreakpoint < Breakpoint
-    attr_reader :path, :line, :iseq
+    attr_reader :path, :line, :iseq, :cond, :oneshot, :hook_call, :command
 
-    def initialize path, line, cond: nil, oneshot: false, hook_call: true, command: nil
+    def self.copy bp, root_iseq
+      nbp = LineBreakpoint.new bp.path, bp.line,
+                               cond: bp.cond, oneshot: bp.oneshot, hook_call: bp.hook_call,
+                               command: bp.command, skip_activate: true
+      nbp.try_activate root_iseq
+      nbp
+    end
+
+    def initialize path, line, cond: nil, oneshot: false, hook_call: true, command: nil, skip_activate: false
       @line = line
       @oneshot = oneshot
       @hook_call = hook_call
@@ -146,7 +154,7 @@ def initialize path, line, cond: nil, oneshot: false, hook_call: true, command:
 
       super(cond, command, path)
 
-      try_activate
+      try_activate unless skip_activate
       @pending = !@iseq
     end
 

lib/debug/session.rb

@@ -1589,6 +1589,7 @@ def in_subsession?
 
     def on_load iseq, src
       DEBUGGER__.info "Load #{iseq.absolute_path || iseq.path}"
+
       file_path, reloaded = @sr.add(iseq, src)
       @ui.event :load, file_path, reloaded
 
@@ -1601,6 +1602,17 @@ def on_load iseq, src
           bp.try_activate iseq
         end
       end
+
+      if reloaded
+        @bps.find_all do |key, bp|
+          LineBreakpoint === bp && DEBUGGER__.compare_path(bp.path, file_path)
+        end.each do |_key, bp|
+          @bps.delete bp.key # to allow duplicate
+          if nbp = LineBreakpoint.copy(bp, iseq)
+            add_bp nbp
+          end
+        end
+      end
     end
 
     def resolve_path file

test/console/break_test.rb

@@ -748,4 +748,44 @@ def test_the_path_option_supersede_skip_path_config
       end
     end
   end
+
+  class BreakAtLinesReloadTest < ConsoleTestCase
+    def extra_file
+      <<~RUBY
+      def foo  # 1
+        a = 10 # 2
+        b = 20 # 3
+        c = 30 # 4
+      end
+      RUBY
+    end
+
+    def program path
+      <<~RUBY
+      1| load #{path.dump}
+      2| foo()
+      3| load #{path.dump}
+      4| foo()
+      RUBY
+    end
+
+    def test_break_on_realoded_file
+      with_extra_tempfile do |extra_file|
+        debug_code(program(extra_file.path)) do
+          type "break #{extra_file.path}:2 do: p :xyzzy"
+          type "break #{extra_file.path}:3"
+
+          type 'c'
+          assert_line_num 3
+          assert_line_text(/xyzzy/)
+
+          type 'c'
+          assert_line_num 3         # should stop at reloaded file
+          assert_line_text(/xyzzy/) # should do at line 2
+
+          type 'c'
+        end
+      end
+    end
+  end
 end