-#1904652 patch: Fail more gracefully on bad fstatat.

Do not crash if an fstatat is not allowed, but fail in the way
documented by the fstatat manpage (set errno to EACCES and return -1).
Otherwise, QtWebEngine always crashes.

qtwebengine-everywhere-src-5.15.2-#1904652.patch

@@ -22,16 +22,17 @@ diff -ur qtwebengine-everywhere-src-5.15.2/src/3rdparty/chromium/sandbox/linux/s
      return Error(fs_denied_errno);
 diff -ur qtwebengine-everywhere-src-5.15.2/src/3rdparty/chromium/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc qtwebengine-everywhere-src-5.15.2-#1904652/src/3rdparty/chromium/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc
 --- qtwebengine-everywhere-src-5.15.2/src/3rdparty/chromium/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc	2020-11-07 02:22:36.000000000 +0100
-+++ qtwebengine-everywhere-src-5.15.2-#1904652/src/3rdparty/chromium/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc	2021-01-20 02:44:06.132477575 +0100
-@@ -6,6 +6,7 @@
++++ qtwebengine-everywhere-src-5.15.2-#1904652/src/3rdparty/chromium/sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc	2021-01-22 19:02:55.651668257 +0100
+@@ -6,6 +6,8 @@
  
  #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
  
++#include <errno.h>
 +#include <fcntl.h>
  #include <stddef.h>
  #include <stdint.h>
  #include <sys/syscall.h>
-@@ -353,6 +354,32 @@
+@@ -353,6 +355,35 @@
    return -ENOSYS;
  }
  
@@ -49,6 +50,9 @@ diff -ur qtwebengine-everywhere-src-5.15.2/src/3rdparty/chromium/sandbox/linux/s
 +          && args.args[3] == static_cast<uint64_t>(AT_EMPTY_PATH)) {
 +        return sandbox::sys_fstat64(static_cast<int>(args.args[0]),
 +                                    reinterpret_cast<struct stat64 *>(args.args[2]));
++      } else {
++        errno = EACCES;
++        return -1;
 +      }
 +      break;
 +#endif
@@ -64,7 +68,7 @@ diff -ur qtwebengine-everywhere-src-5.15.2/src/3rdparty/chromium/sandbox/linux/s
  bpf_dsl::ResultExpr CrashSIGSYS() {
    return bpf_dsl::Trap(CrashSIGSYS_Handler, NULL);
  }
-@@ -385,6 +412,10 @@
+@@ -385,6 +416,10 @@
    return bpf_dsl::Trap(SIGSYSSchedHandler, NULL);
  }