[OE-core] [PATCH 2/3] image.bbclass: improve setup of flags

[Ed Bartosh]

Replaced setVarFlag calls to appendVarFlag to allow
modification of prefuncs, postfuncs and subimages flags
in inherited image classes.

[YOCTO #11372]

Signed-off-by: Ed Bartosh <ed.bartosh at linux.intel.com>
---
 meta/classes/image.bbclass | 7 ++++---
 1 file 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')
 
-- 
2.1.4