From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Wed, 18 Jul 2018 00:58:44 +0200
Subject: [PATCH] blscfg: Don't attempt to sort by version if not present in
 all BLS files

Commit a16805341cc ("blscfg: sort BLS entries by 'version' field") made to
sort by the version field take precedence over the BLS fragment file name.

But it also uses the lack of the version field in one BLS fragment as sort
criterion, which means that entries could be wrongly sorted if one of them
doesn't have a version field and others do.

So only sort by version if all the BLS entries have this field defined,
otherwise just fallback to sorting by the BLS file name.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Suggested-by: Will Thompson <wjt@endlessm.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---
 grub-core/commands/blscfg.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/grub-core/commands/blscfg.c b/grub-core/commands/blscfg.c
index 321c93069f2..69bfb5db295 100644
--- a/grub-core/commands/blscfg.c
+++ b/grub-core/commands/blscfg.c
@@ -324,23 +324,21 @@ finish:
 /* return 1: p0 is newer than p1 */
 /*        0: p0 and p1 are the same version */
 /*       -1: p1 is newer than p0 */
-static int bls_cmp(const void *p0, const void *p1, void *state UNUSED)
+static int bls_cmp(const void *p0, const void *p1, void *state)
 {
   struct bls_entry * e0 = *(struct bls_entry **)p0;
   struct bls_entry * e1 = *(struct bls_entry **)p1;
+  bool use_version = *(bool *)state;
   const char *v0, *v1;
   int r;
 
-  v0 = bls_get_val(e0, "version", NULL);
-  v1 = bls_get_val(e1, "version", NULL);
+  if (use_version) {
+    v0 = bls_get_val(e0, "version", NULL);
+    v1 = bls_get_val(e1, "version", NULL);
 
-  if (v0 && !v1)
-    return -1;
-  if (!v0 && v1)
-    return 1;
-
-  if ((r = vercmp(v0, v1)) != 0)
-    return r;
+    if ((r = vercmp(v0, v1)) != 0)
+      return r;
+  }
 
   return vercmp(e0->filename, e1->filename);
 }
@@ -692,6 +690,7 @@ static int find_entry (const char *filename,
   grub_device_t blsdir_dev = NULL;
   const char *blsdir = NULL;
   char *saved_env_buf = NULL;
+  bool use_version = true;
   int fallback = 0;
   int r = 0;
   const char *devid = grub_env_get ("boot");
@@ -819,7 +818,13 @@ read_fallback:
   }
 
   grub_dprintf ("blscfg", "Sorting %d entries\n", nentries);
-  grub_qsort(&entries[0], nentries, sizeof (struct bls_entry *), bls_cmp, NULL);
+
+  for (r = 0; r < nentries && use_version; r++) {
+    if (!bls_get_val(entries[r], "version", NULL))
+      use_version = false;
+  }
+
+  grub_qsort(&entries[0], nentries, sizeof (struct bls_entry *), bls_cmp, &use_version);
 
   grub_dprintf ("blscfg", "%s Creating %d entries from bls\n", __func__, nentries);
   for (r = nentries - 1; r >= 0; r--)