win32: support "app exec link" reparse points

Reparse points with the tag IO_REPARSE_TAG_APPEXECLINK are present
in ~/AppData/Local/Microsoft/WindowsApps in Windows 10 and 11.
They are:

   Used by Universal Windows Platform (UWP) packages to encode
   information that allows the application to be launched by
   CreateProcess.

Modify readlink(2) and lsattr(1) to treat them as symbolic links, in
much the same way as was done previously for junctions.  They aren't
really symbolic links but they're similar.

Costs 128-160 bytes.

(GitHub issue #327)

2 files changed, 7 insertions, 0 deletions

diff --git a/e2fsprogs/e2fs_lib.c b/e2fsprogs/e2fs_lib.c
index 031f5e06b..4a4db1a13 100644
--- a/e2fsprogs/e2fs_lib.c
+++ b/e2fsprogs/e2fs_lib.c
@@ -135,6 +135,9 @@ void print_e2flags_long(struct stat *sb)
                                 case IO_REPARSE_TAG_MOUNT_POINT:
                                         ln = "Junction";
                                         break;
+                                case IO_REPARSE_TAG_APPEXECLINK:
+                                        ln = "App_Exec_Link";
+                                        break;
                                 }
                         }
                         fputs(ln, stdout);
@@ -174,6 +177,9 @@ void print_e2flags(struct stat *sb)
                         case IO_REPARSE_TAG_MOUNT_POINT:
                                 c = 'j';
                                 break;
+                        case IO_REPARSE_TAG_APPEXECLINK:
+                                c = 'A';
+                                break;
                         }
                 }
 #endif
diff --git a/e2fsprogs/lsattr.c b/e2fsprogs/lsattr.c
index a6c4a27e9..87fdb78b3 100644
--- a/e2fsprogs/lsattr.c
+++ b/e2fsprogs/lsattr.c
@@ -47,6 +47,7 @@
 //usage:     "\n\nAttributes:\n"
 //usage:     "\n        j       Junction"
 //usage:     "\n        l       Symbolic link"
+//usage:     "\n        A       App exec link"
 //usage:     "\n        R       Reparse point"
 //usage:     "\n        o       Offline"
 //usage:     "\n        e       Encrypted"