[gnome-continuous-yocto/gnomeostree-3.28-rocko: 26/8267] image.bbclass: don't execute compression commands multiple times

[Emmanuele Bassi <ebassi src gnome org>]

commit d73b756d822f29c7616a9e86e5fe422f63d3512e
Author: Alexander D. Kanevskiy <kad kad name>
Date:   Thu Apr 21 12:47:27 2016 +0300

    image.bbclass: don't execute compression commands multiple times
    
    In case of chained conversion methods are used via COMPRESS_CMD_*
    there is chance that some of steps would be executed multiple times.
    
    [YOCTO #9482]
    
    (From OE-Core rev: 94f61c2682e5cfd819ac84535650c3e0a654415a)
    
    Signed-off-by: Alexander D. Kanevskiy <kad kad name>
    Signed-off-by: Ross Burton <ross burton intel com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/classes/image.bbclass |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 9ba6011..4542e95 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -402,9 +402,13 @@ python () {
                     # Create input image first.
                     gen_conversion_cmds(type)
                     localdata.setVar('type', type)
-                    cmds.append("\t" + localdata.getVar("COMPRESS_CMD_" + ctype, True))
+                    cmd = "\t" + localdata.getVar("COMPRESS_CMD_" + ctype, True)
+                    if cmd not in cmds:
+                        cmds.append(cmd)
                     vardeps.add('COMPRESS_CMD_' + ctype)
-                    subimages.append(type + "." + ctype)
+                    subimage = type + "." + ctype
+                    if subimage not in subimages:
+                        subimages.append(subimage)
                     if type not in alltypes:
                         rm_tmp_images.add(localdata.expand("${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type}"))