Merge remote-tracking branch 'upstream/main' into vs2019

.github/workflows/build.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 jobs:
   linux:
     name: Linux
-    runs-on: ubuntu-16.04
+    runs-on: ubuntu-18.04
     steps:
     - uses: actions/checkout@v2
     - name: Install Dependencies

code/qcommon/files.c

@@ -2933,7 +2933,9 @@ void FS_AddGameDirectory( const char *path, const char *dir ) {
 	// Get .pk3 files
 	pakfiles = Sys_ListFiles(curpath, ".pk3", NULL, &numfiles, qfalse);
 
-	qsort( pakfiles, numfiles, sizeof(char*), paksort );
+	if ( pakfiles ) {
+		qsort( pakfiles, numfiles, sizeof(char*), paksort );
+	}
 
 	if ( fs_numServerPaks ) {
 		numdirs = 0;