[PATCH] */*/ glob pattern bug

[spagoveanu]

When using gnu make on a system with glibc (eg. Debian Stretch),
a glob pattern ending in a slash is also matching regular files,
but only in subdirectories:

$ mkdir -p dir/subdir
$ cd dir
$ touch file1 subdir/file2
$ echo 'test:; @echo $(wildcard */ */*/)' | make -f -
subdir/ subdir/file2
$ echo 'test: */ */*/; @echo "$?" != */ */*/' | make -f -
subdir/ subdir/file2 != subdir/ */*/

It happens because in the gl->gl_readdir callback supplied to glob(),
dirent->d_type is set to DT_UNKNOWN, and the glob() implementation
in glibc assumes that such a directory entry *cannot* possibly be a
regular file.

In the patch below I'm simply passing the actual d_type down to glob();
this is the right thing to do even if they fix it in glibc, because
it saves an extra stat() syscall for each dirent.

diff --git a/src/dir.c b/src/dir.c
index c343e4c..f546766 100644
--- a/src/dir.c
+++ b/src/dir.c
@@ -407,6 +407,7 @@ struct dirfile
     const char *name;           /* Name of the file.  */
     size_t length;
     short impossible;           /* This file is impossible.  */
+    unsigned char type;
   };
 
 static unsigned long
@@ -731,6 +732,9 @@ dir_contents_file_exists_p (struct directory_contents *dir,
 #else
           df->name = strcache_add_len (d->d_name, len);
 #endif
+#ifdef _DIRENT_HAVE_D_TYPE
+          df->type = d->d_type;
+#endif
           df->length = len;
           df->impossible = 0;
           hash_insert_at (&dir->dirfiles, df, dirfile_slot);
@@ -1242,7 +1246,7 @@ read_dirstream (__ptr_t stream)
           d->d_namlen = len - 1;
 #endif
 #ifdef _DIRENT_HAVE_D_TYPE
-          d->d_type = DT_UNKNOWN;
+          d->d_type = df->type;
 #endif
           memcpy (d->d_name, df->name, len);
           return d;