Fix SGB JOYP incrementing behavior [endrift]

Fix GB JOYP read setting d6+d7 in SameBoy
Improve headered IPS patch handling

bsnes/gb/Core/memory.c

@@ -310,6 +310,7 @@ static uint8_t read_high_memory(GB_gameboy_t *gb, uint16_t addr)
                        (gb->apu.is_active[GB_WAVE] ? (gb->apu.samples[GB_WAVE]) : 0);
             case GB_IO_JOYP:
                 GB_timing_sync(gb);
+                return gb->io_registers[addr & 0xFF] | 0xC0;
             case GB_IO_TMA:
             case GB_IO_LCDC:
             case GB_IO_SCY:

bsnes/sfc/coprocessor/icd/icd.cpp

@@ -147,9 +147,8 @@ auto ICD::power(bool reset) -> void {
   for(auto& packet : this->packet) packet = {};
   packetSize = 0;
 
-  joypID = 3;
-  joyp14Lock = 0;
-  joyp15Lock = 0;
+  joypID = 0;
+  joypLock = 1;
   pulseLock = 1;
   strobeLock = 0;
   packetLock = 0;

bsnes/sfc/coprocessor/icd/icd.hpp

@@ -44,8 +44,7 @@ private:
   uint7 packetSize;
 
   uint2 joypID;
-  uint1 joyp14Lock;
-  uint1 joyp15Lock;
+  uint1 joypLock;
   uint1 pulseLock;
   uint1 strobeLock;
   uint1 packetLock;

bsnes/sfc/coprocessor/icd/interface.cpp

@@ -27,9 +27,8 @@ auto ICD::apuWrite(float left, float right) -> void {
 auto ICD::joypWrite(bool p14, bool p15) -> void {
   //joypad handling
   if(p14 == 1 && p15 == 1) {
-    if(joyp14Lock == 0 && joyp15Lock == 0) {
-      joyp14Lock = 1;
-      joyp15Lock = 1;
+    if(joypLock == 0) {
+      joypLock = 1;
       joypID++;
       if(mltReq == 0) joypID &= 0;  //1-player mode
       if(mltReq == 1) joypID &= 1;  //2-player mode
@@ -51,30 +50,30 @@ auto ICD::joypWrite(bool p14, bool p15) -> void {
 
   GB_icd_set_joyp(&sameboy, input);
 
-  if(p14 == 0 && p15 == 1) joyp14Lock = 0;
-  if(p14 == 1 && p15 == 0) joyp15Lock = 0;
+  if(p14 == 0 && p15 == 1);
+  if(p14 == 1 && p15 == 0) joypLock ^= 1;
 
   //packet handling
   if(p14 == 0 && p15 == 0) {  //pulse
-    pulseLock = false;
+    pulseLock = 0;
     packetOffset = 0;
     bitOffset = 0;
-    strobeLock = true;
-    packetLock = false;
+    strobeLock = 1;
+    packetLock = 0;
     return;
   }
 
-  if(pulseLock) return;
+  if(pulseLock == 1) return;
 
   if(p14 == 1 && p15 == 1) {
-    strobeLock = false;
+    strobeLock = 0;
     return;
   }
 
-  if(strobeLock) {
+  if(strobeLock == 1) {
     if(p14 == 1 || p15 == 1) {  //malformed packet
-      packetLock = false;
-      pulseLock = true;
+      packetLock = 0;
+      pulseLock = 1;
       bitOffset = 0;
       packetOffset = 0;
     } else {
@@ -85,18 +84,21 @@ auto ICD::joypWrite(bool p14, bool p15) -> void {
   //p14:0, p15:1 = 0
   //p14:1, p15:0 = 1
   bool bit = p15 == 0;
-  strobeLock = true;
+  strobeLock = 1;
 
-  if(packetLock) {
+  if(packetLock == 1) {
     if(p14 == 0 && p15 == 1) {
       if((joypPacket[0] >> 3) == 0x11) {
         mltReq = joypPacket[1] & 3;
-        joypID = 3;
+        if(mltReq == 0) joypID &= 0;  //1-player mode
+        if(mltReq == 1) joypID &= 1;  //2-player mode
+        if(mltReq == 2) joypID &= 3;  //4-player mode (unverified; but the most likely behavior)
+        if(mltReq == 3) joypID &= 3;  //4-player mode
       }
 
       if(packetSize < 64) packet[packetSize++] = joypPacket;
-      packetLock = false;
-      pulseLock = true;
+      packetLock = 0;
+      pulseLock = 1;
     }
     return;
   }
@@ -107,5 +109,5 @@ auto ICD::joypWrite(bool p14, bool p15) -> void {
   joypPacket[packetOffset] = bitData;
   if(++packetOffset) return;
 
-  packetLock = true;
+  packetLock = 1;
 }

bsnes/sfc/coprocessor/icd/serialization.cpp

@@ -16,8 +16,7 @@ auto ICD::serialize(serializer& s) -> void {
   s.integer(packetSize);
 
   s.integer(joypID);
-  s.integer(joyp14Lock);
-  s.integer(joyp15Lock);
+  s.integer(joypLock);
   s.integer(pulseLock);
   s.integer(strobeLock);
   s.integer(packetLock);

bsnes/target-bsnes/program/patch.cpp

@@ -71,7 +71,6 @@ auto Program::applyPatchIPS(vector<uint8_t>& data, string location) -> bool {
     offset |= patch(index++, 0) <<  8;
     offset |= patch(index++, 0) <<  0;
     if(headered) offset -= 512;
-    if(offset < 0 || offset > 16_MiB) return false;  //sanity check
 
     uint16_t length = 0;
     length |= patch(index++, 0) << 8;
@@ -84,9 +83,16 @@ auto Program::applyPatchIPS(vector<uint8_t>& data, string location) -> bool {
 
       uint8_t fill = patch(index++, 0);
 
-      while(repeat--) data(offset++) = fill;
+      while(repeat--) {
+        if(offset >= 0) data(offset) = fill;
+        offset++;
+      }
     } else {
-      while(length--) data(offset++) = patch(index++, 0);
+      while(length--) {
+        if(offset >= 0) data(offset) = patch(index, 0);
+        offset++;
+        index++;
+      }
     }
   }