support B2 patches on BB

src/FunctionCompiler.cc

@@ -392,8 +392,9 @@ shared_ptr<const Menu> FunctionCodeIndex::patch_switches_menu(
 }
 
 bool FunctionCodeIndex::patch_menu_empty(uint32_t specific_version) const {
+  uint32_t mask = specific_version_is_indeterminate(specific_version) ? 0xFF000000 : 0xFFFFFFFF;
   for (const auto& it : this->menu_item_id_and_specific_version_to_patch_function) {
-    if ((it.first & 0xFF000000) == (specific_version & 0xFF000000)) {
+    if ((it.first & mask) == (specific_version & mask)) {
       return false;
     }
   }

src/ReceiveCommands.cc

@@ -1071,6 +1071,48 @@ static void on_93_BB(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
   } else {
     string version_string = config_data.as_string();
     strip_trailing_zeroes(version_string);
+    // If the version string starts with "Ver.", assume it's Sega and apply the
+    // normal version encoding logic. Otherwise, assume it's a community mod,
+    // almost all of which are based on TethVer12513, so assume that version
+    // otherwise.
+    if (true || starts_with(version_string, "Ver.")) {
+      // Basic algorithm: take all numeric characters from the version string
+      // and ignore everything else. Treat that as a decimal integer, then
+      // base36-encode it into the low 3 bytes of specific_version.
+      uint64_t version = 0;
+      for (char ch : version_string) {
+        if (isdigit(ch)) {
+          version = (version * 10) + (ch - '0');
+        }
+      }
+      uint8_t shift = 0;
+      uint32_t specific_version = 0;
+      while (version) {
+        if (shift > 16) {
+          throw runtime_error("invalid version string");
+        }
+        uint8_t ch = (version % 36) + '0';
+        version /= 36;
+        if (ch > '9') {
+          ch += 7;
+        }
+        specific_version |= (ch << shift);
+        shift += 8;
+      }
+      if (!(specific_version & 0x00FF0000)) {
+        specific_version |= 0x00300000;
+      }
+      if (!(specific_version & 0x0000FF00)) {
+        specific_version |= 0x00003000;
+      }
+      if (!(specific_version & 0x000000FF)) {
+        specific_version |= 0x00000030;
+      }
+      c->config.specific_version = 0x35000000 | specific_version;
+
+    } else {
+      c->config.specific_version = 0x35394E4C; // 59NL
+
       // Note: Tethealla PSOBB is actually Japanese PSOBB, but with most of the
       // files replaced with English text/graphics/etc. For this reason, it still
       // reports its language as Japanese, so we have to account for that
@@ -1080,6 +1122,7 @@ static void on_93_BB(shared_ptr<Client> c, uint16_t, uint32_t, string& data) {
         c->config.set_flag(Client::Flag::FORCE_ENGLISH_LANGUAGE_BB);
       }
     }
+  }
   c->channel.language = c->config.check_flag(Client::Flag::FORCE_ENGLISH_LANGUAGE_BB) ? 1 : base_cmd.language;
   c->bb_connection_phase = base_cmd.connection_phase;
   c->bb_character_index = base_cmd.character_slot;

src/Version.cc

@@ -305,10 +305,8 @@ bool specific_version_is_xb(uint32_t specific_version) {
 }
 
 bool specific_version_is_bb(uint32_t specific_version) {
-  // TODO: We should actually find a way to determine BB specific_versions, but
+  // BB specific_versions are 5XXX, where X is an encoding of the revision number
-  // there are so many mods out there, and there's a patch server anyway, so it
+  return (specific_version & 0xFF000000) == 0x35000000;
-  // seems not worth the effort
-  return specific_version == 0x35303030;
 }
 
 const char* file_path_token_for_version(Version version) {

system/client-functions/System/WriteCodeBlocksBB.x86.inc.s

@@ -0,0 +1,29 @@
+start:
+  push    ebx
+  jmp     get_patch_data_ptr
+get_patch_data_ptr_ret:
+  pop     ebx                   # ebx = patch header
+
+apply_next_patch:
+  cmp     dword [ebx + 4], 0
+  jne     copy_code_and_apply_again
+  pop     ebx
+  mov     eax, 1
+  ret
+
+copy_code_and_apply_again:
+  xor     ecx, ecx              # ecx = offset
+  mov     edx, [ebx]            # edx = dest addr
+copy_next_byte:
+  mov     al, [ebx + ecx + 8]   # copy one byte to dest
+  mov     [edx + ecx], al
+  inc     ecx                   # offset++
+  cmp     [ebx + 4], ecx        # check if all bytes have been copied
+  jne     copy_next_byte
+
+  lea     ebx, [ebx + ecx + 8]  # advance to next block
+  jmp     apply_next_patch
+
+get_patch_data_ptr:
+  call    get_patch_data_ptr_ret
+first_patch_header: