[gnome-continuous-yocto/gnomeostree-3.28-rocko: 6349/8267] image.bbclass: improve setup of flags

[Emmanuele Bassi <ebassi src gnome org>]

commit 201e4acefba2e807ae04b42185cabe7ca7066823
Author: Ed Bartosh <ed bartosh linux intel com>
Date:   Wed Jun 14 12:07:05 2017 +0300

    image.bbclass: improve setup of flags
    
    Replaced setVarFlag calls to appendVarFlag to allow
    modification of prefuncs, postfuncs and subimages flags
    in inherited image classes.
    
    [YOCTO #11372]
    
    (From OE-Core rev: 6690f3ab43c04fa7cff7215d4a5d8d639e41aed8)
    
    Signed-off-by: Ed Bartosh <ed bartosh linux intel com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/classes/image.bbclass |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index ff4eda1..e18ac72 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -496,9 +496,10 @@ python () {
         d.setVar(task, '\n'.join(cmds))
         d.setVarFlag(task, 'func', '1')
         d.setVarFlag(task, 'fakeroot', '1')
-        d.setVarFlag(task, 'prefuncs', debug + 'set_image_size')
-        d.setVarFlag(task, 'postfuncs', 'create_symlinks')
-        d.setVarFlag(task, 'subimages', ' '.join(subimages))
+
+        d.appendVarFlag(task, 'prefuncs', ' ' + debug + ' set_image_size')
+        d.appendVarFlag(task, 'postfuncs', ' create_symlinks')
+        d.appendVarFlag(task, 'subimages', ' ' + ' '.join(subimages))
         d.appendVarFlag(task, 'vardeps', ' '.join(vardeps))
         d.appendVarFlag(task, 'vardepsexclude', 'DATETIME')