From 96bdc184d8b9f4123aa15bab749e0d885a11dd40 Mon Sep 17 00:00:00 2001
From: Steven Hugg <hugg@fasterlight.com>
Date: Sun, 29 Dec 2019 12:01:10 -0600
Subject: [PATCH] nes/vcs: fix crash if click disassembler before rom loads

---
 src/platform/nes.ts       | 8 +++++++-
 src/platform/vcs.ts       | 4 ++--
 test/cli/testplatforms.js | 1 +
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/platform/nes.ts b/src/platform/nes.ts
index d6d17e24..c882e6bc 100644
--- a/src/platform/nes.ts
+++ b/src/platform/nes.ts
@@ -299,7 +299,13 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
   // TODO don't need to save ROM?
   saveState() {
     //var s = $.extend(true, {}, this.nes);
-    var s = this.nes.toJSON();
+    var s;
+    if (this.nes.mmap) {
+      s = this.nes.toJSON();
+    } else {
+      console.log("no nes.mmap!");
+      s = { cpu: this.nes.cpu.toJSON(), ppu: this.nes.ppu.toJSON() };
+    }
     s.c = s.cpu;
     this.copy6502REGvars(s.c);
     s.b = s.cpu.mem = s.cpu.mem.slice(0);
diff --git a/src/platform/vcs.ts b/src/platform/vcs.ts
index a460ceb2..7fad8526 100644
--- a/src/platform/vcs.ts
+++ b/src/platform/vcs.ts
@@ -187,8 +187,8 @@ class VCSPlatform extends BasePlatform {
     return state;
   }
   fixState(state) {
-    var ofs = state.ca.bo || 0;
-    if (state.ca.fo && (state.c.PC & 0xfff) >= 2048)
+    var ofs = (state.ca && state.ca.bo) || 0;
+    if (state.ca && state.ca.fo && (state.c.PC & 0xfff) >= 2048)
       ofs = state.ca.fo; // 3E/3F fixed-slice formats
     // TODO: for batari BASIC
     state.c.EPC = state.c.PC + ofs; // EPC = effective PC for ROM
diff --git a/test/cli/testplatforms.js b/test/cli/testplatforms.js
index 0abe5975..7d26971c 100644
--- a/test/cli/testplatforms.js
+++ b/test/cli/testplatforms.js
@@ -118,6 +118,7 @@ function testPlatform(platid, romname, maxframes, callback) {
     var platform = new emu.PLATFORMS[platid](emudiv);
     var rec = new recorder.StateRecorderImpl(platform);
     platform.start();
+    assert.ok(platform.saveState()); // can save before ROM load?
     var rom = fs.readFileSync('./test/roms/' + platid + '/' + romname);
     rom = new Uint8Array(rom);
     platform.loadROM("ROM", rom);