[Libguestfs] [PATCH] Fix detection of an existing grub entry

[Matthew Booth]

There were 2 issues in the code which checked for an existing grub entry before
adding a new one.

Firstly, it didn't take account of the fact that the passed-in kernel path is
relative to root, whereas the grub entry is relative to the grub filesystem,
which is normally /boot.

Secondly, it expected return from inside eval{} to exit the function, when in
fact it only exits the eval.
---
 lib/Sys/VirtV2V/Converter/RedHat.pm |   16 +++++++---------
 1 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/lib/Sys/VirtV2V/Converter/RedHat.pm b/lib/Sys/VirtV2V/Converter/RedHat.pm
index 0a4f829..d8f9141 100644
--- a/lib/Sys/VirtV2V/Converter/RedHat.pm
+++ b/lib/Sys/VirtV2V/Converter/RedHat.pm
@@ -1500,23 +1500,21 @@ sub _check_grub
 {
     my ($version, $kernel, $g, $desc) = @_;
 
+    my $grubfs = $desc->{boot}->{grub_fs};
+    my $prefix = $grubfs eq '/boot' ? '' : '/boot';
+
     # Nothing to do if there's already a grub entry
-    eval {
+    return if eval {
         foreach my $augpath
             ($g->aug_match('/files/boot/grub/menu.lst/title/kernel'))
         {
-            return if ($g->aug_get($augpath) eq $kernel);
+            return 1 if ($grubfs.$g->aug_get($augpath) eq $kernel);
         }
+
+        return 0
     };
     augeas_error($g, $@) if ($@);
 
-    my $prefix;
-    if ($desc->{boot}->{grub_fs} eq "/boot") {
-        $prefix = '';
-    } else {
-        $prefix = '/boot';
-    }
-
     my $initrd = "$prefix/initrd-$version.img";
     $kernel =~ m{^/boot/(.*)$} or die("kernel in unexpected location: $kernel");
     my $vmlinuz = "$prefix/$1";
-- 
1.7.3.5