upgpkg: discord 0.0.55-2: refactor, fix autostart, add deps, use wayland

* Slightly refactor PKGBUILD
* Fix autostart desktop file
* Add optional dependency used in official arch package
* Include patcher to allow Krisp noise suppression support
* Add install file to inform user about this change
* Use Wayland instead of Xwayland in a Wayland session by setting
  Electron flag `ozone-platform-hint` to auto (default is X11)

1 files changed, 83 insertions, 0 deletions

diff --git a/krisp-patcher.py b/krisp-patcher.py
new file mode 100644
index 000000000000..559729098ab7
--- /dev/null
+++ b/krisp-patcher.py
@@ -0,0 +1,83 @@
+import sys
+import shutil
+
+from elftools.elf.elffile import ELFFile
+from capstone import *
+from capstone.x86 import *
+
+if len(sys.argv) < 2:
+    print(f"Usage: {sys.argv[0]} [path to discord_krisp.node]")
+    # "Unix programs generally use 2 for command line syntax errors and 1 for all other kind of errors."
+    sys.exit(2)
+
+executable = sys.argv[1]
+
+elf = ELFFile(open(executable, "rb"))
+symtab = elf.get_section_by_name('.symtab')
+
+krisp_initialize_address = symtab.get_symbol_by_name("_ZN7discord15KrispInitializeEv")[0].entry.st_value
+isSignedByDiscord_address = symtab.get_symbol_by_name("_ZN7discord4util17IsSignedByDiscordERKNSt4__Cr12basic_stringIcNS1_11char_traitsIcEENS1_9allocatorIcEEEE")[0].entry.st_value
+
+text = elf.get_section_by_name('.text')
+text_start = text['sh_addr']
+text_start_file = text['sh_offset']
+# This seems to always be zero (.text starts at the right offset in the file). Do it just in case?
+address_to_file = text_start_file - text_start
+
+# Done with the ELF now.
+# elf.close()
+
+krisp_initialize_offset = krisp_initialize_address - address_to_file
+isSignedByDiscord_offset = krisp_initialize_address - address_to_file
+
+f = open(executable, "rb")
+f.seek(krisp_initialize_offset)
+krisp_initialize = f.read(64)
+f.close()
+
+# States
+found_issigned_by_discord_call = False
+found_issigned_by_discord_test = False
+found_issigned_by_discord_je = False
+found_already_patched = False
+je_location = None
+
+# We are looking for a call to IsSignedByDiscord, followed by a test, followed by a je.
+# Then we patch the je into a two byte nop.
+
+md = Cs(CS_ARCH_X86, CS_MODE_64)
+md.detail = True
+for i in md.disasm(krisp_initialize, krisp_initialize_address):
+    if i.id == X86_INS_CALL:
+        if i.operands[0].type == X86_OP_IMM:
+            if i.operands[0].imm == isSignedByDiscord_address:
+                found_issigned_by_discord_call = True
+
+    if i.id == X86_INS_TEST:
+        if found_issigned_by_discord_call:
+            found_issigned_by_discord_test = True
+
+    if i.id == X86_INS_JE:
+        if found_issigned_by_discord_test:
+            found_issigned_by_discord_je = True
+            je_location = i.address
+            break
+
+    if i.id == X86_INS_NOP:
+        if found_issigned_by_discord_test:
+            found_already_patched = True
+            break
+
+if je_location:
+    print(f"Found patch location: 0x{je_location:x}")
+
+    shutil.copyfile(executable, executable + ".orig")
+    f = open(executable, 'rb+')
+    f.seek(je_location - address_to_file)
+    f.write(b'\x66\x90')  # Two byte NOP
+    f.close()
+else:
+    if found_already_patched:
+        print("Couldn't find patch location - already patched.")
+    else:
+        print("Couldn't find patch location - review manually. Sorry.")