Fixing double insertion of encoding in locale.gen/locale.conf (#1421)

* A temporary fix for #1200, in the long run we need something like what was mentioned in the issue comments: https://github.com/archlinux/archinstall/issues/1200#issuecomment-1212754806

* Enabled the use of modifier detection and getting it in right

* Mistaken a split

* Adding less strict decoding of output log, this in order to handle the more correct locale generation introduced in this PR.

archinstall/lib/general.py

@@ -444,7 +444,7 @@ class SysCommand:
 
 	def __repr__(self, *args :List[Any], **kwargs :Dict[str, Any]) -> str:
 		if self.session:
-			return self.session._trace_log.decode('UTF-8')
+			return self.session._trace_log.decode('UTF-8', errors='backslashreplace')
 		return ''
 
 	def __json__(self) -> Dict[str, Union[str, bool, List[str], Dict[str, Any], Optional[bool], Optional[Dict[str, Any]]]]:

archinstall/lib/installer.py

@@ -443,10 +443,27 @@ class Installer:
 		if not len(locale):
 			return True
 
+		modifier = ''
+
+		# This is a temporary patch to fix #1200
+		if '.' in locale:
+			locale, potential_encoding = locale.split('.', 1)
+
+			# Override encoding if encoding is set to the default parameter
+			# and the "found" encoding differs.
+			if encoding == 'UTF-8' and encoding != potential_encoding:
+				encoding = potential_encoding
+
+		# Make sure we extract the modifier, that way we can put it in if needed.
+		if '@' in locale:
+			locale, modifier = locale.split('@', 1)
+			modifier = f"@{modifier}"
+		# - End patch
+
 		with open(f'{self.target}/etc/locale.gen', 'a') as fh:
-			fh.write(f'{locale}.{encoding} {encoding}\n')
+			fh.write(f'{locale}.{encoding}{modifier} {encoding}\n')
 		with open(f'{self.target}/etc/locale.conf', 'w') as fh:
-			fh.write(f'LANG={locale}.{encoding}\n')
+			fh.write(f'LANG={locale}.{encoding}{modifier}\n')
 
 		return True if SysCommand(f'/usr/bin/arch-chroot {self.target} locale-gen').exit_code == 0 else False