From 31b459ac8487b3929627697211d4b862d1a56440 Mon Sep 17 00:00:00 2001
From: thrust26 <tjentzsch@yahoo.de>
Date: Sat, 16 Dec 2017 09:46:25 +0100
Subject: [PATCH] fixed #269

---
 src/debugger/Debugger.cxx | 40 ++++++++++++++++++++++-----------------
 src/debugger/Debugger.hxx | 13 ++++++++-----
 src/emucore/M6502.cxx     |  2 +-
 3 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/src/debugger/Debugger.cxx b/src/debugger/Debugger.cxx
index 308ec73a0..1f4a5c16a 100644
--- a/src/debugger/Debugger.cxx
+++ b/src/debugger/Debugger.cxx
@@ -270,7 +270,7 @@ void Debugger::loadState(int state)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 int Debugger::step()
 {
-  mySystem.clearDirtyPages();
+  saveOldState();
 
   uInt64 startCycle = mySystem.cycles();
 
@@ -278,7 +278,7 @@ int Debugger::step()
   myOSystem.console().tia().updateScanlineByStep().flushLineCache();
   lockBankswitchState();
 
-  saveOldState("step");
+  addState("step");
   return int(mySystem.cycles() - startCycle);
 }
 
@@ -297,7 +297,7 @@ int Debugger::trace()
   // 32 is the 6502 JSR instruction:
   if(mySystem.peek(myCpuDebug->pc()) == 32)
   {
-    mySystem.clearDirtyPages();
+    saveOldState();
 
     uInt64 startCycle = mySystem.cycles();
     int targetPC = myCpuDebug->pc() + 3; // return address
@@ -306,7 +306,7 @@ int Debugger::trace()
     myOSystem.console().tia().updateScanlineByTrace(targetPC).flushLineCache();
     lockBankswitchState();
 
-    saveOldState("trace");
+    addState("trace");
     return int(mySystem.cycles() - startCycle);
   }
   else
@@ -485,7 +485,7 @@ void Debugger::nextScanline(int lines)
   ostringstream buf;
   buf << "scanline + " << lines;
 
-  mySystem.clearDirtyPages();
+  saveOldState();
 
   unlockBankswitchState();
   while(lines)
@@ -495,7 +495,7 @@ void Debugger::nextScanline(int lines)
   }
   lockBankswitchState();
 
-  saveOldState(buf.str());
+  addState(buf.str());
   myOSystem.console().tia().flushLineCache();
 }
 
@@ -505,7 +505,7 @@ void Debugger::nextFrame(int frames)
   ostringstream buf;
   buf << "frame + " << frames;
 
-  mySystem.clearDirtyPages();
+  saveOldState();
 
   unlockBankswitchState();
   while(frames)
@@ -515,7 +515,7 @@ void Debugger::nextFrame(int frames)
   }
   lockBankswitchState();
 
-  saveOldState(buf.str());
+  addState(buf.str());
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -588,20 +588,24 @@ bool Debugger::patchROM(uInt16 addr, uInt8 value)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Debugger::saveOldState(string rewindMsg)
+void Debugger::saveOldState(bool clearDirtyPages)
 {
+  if (clearDirtyPages)
+    mySystem.clearDirtyPages();
+
   myCartDebug->saveOldState();
   myCpuDebug->saveOldState();
   myRiotDebug->saveOldState();
   myTiaDebug->saveOldState();
+}
 
-  // Add another rewind level to the Undo list
-  if(rewindMsg != "")
-  {
-    RewindManager& r = myOSystem.state().rewindManager();
-    r.addState(rewindMsg);
-    updateRewindbuttons(r);
-  }
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void Debugger::addState(string rewindMsg)
+{
+  // Add another rewind level to the Time Machine buffer
+  RewindManager& r = myOSystem.state().rewindManager();
+  r.addState(rewindMsg);
+  updateRewindbuttons(r);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -612,7 +616,9 @@ void Debugger::setStartState()
 
   // Save initial state and add it to the rewind list (except when in currently rewinding)
   RewindManager& r = myOSystem.state().rewindManager();
-  saveOldState(r.atLast() ? "enter debugger" : "");
+  saveOldState(false);
+  if (r.atLast())
+    addState("enter debugger");
 
   // Set the 're-disassemble' flag, but don't do it until the next scheduled time
   myDialog->rom().invalidate(false);
diff --git a/src/debugger/Debugger.hxx b/src/debugger/Debugger.hxx
index 293063b22..900f064d8 100644
--- a/src/debugger/Debugger.hxx
+++ b/src/debugger/Debugger.hxx
@@ -241,12 +241,15 @@ class Debugger : public DialogContainer
 
   private:
     /**
-      Save state of each debugger subsystem.
-
-      If a message is provided, we assume that a rewind state should
-      be saved with the given message.
+      Save state of each debugger subsystem and, by default, mark all
+      pages as clean (ie, turn off the dirty flag).
     */
-    void saveOldState(string rewindMsg = "");
+    void saveOldState(bool clearDirtyPages = true);
+
+    /**
+      Saves a rewind state with the given message.
+    */
+    void addState(string rewindMsg);
 
     /**
       Set initial state before entering the debugger.
diff --git a/src/emucore/M6502.cxx b/src/emucore/M6502.cxx
index 21b49c3ed..ba0387944 100644
--- a/src/emucore/M6502.cxx
+++ b/src/emucore/M6502.cxx
@@ -233,7 +233,7 @@ bool M6502::execute(uInt32 number)
       cond = evalCondSaveStates();
       if(cond > -1)
       {
-        myDebugger->saveOldState("conditional savestate");
+        myDebugger->addState("conditional savestate");
       }
 #endif  // DEBUGGER_SUPPORT