[gnome-continuous-yocto/gnomeostree-3.28-rocko: 7888/8267] qemurunner: print tail qemu log in case bootlog is empty

[Emmanuele Bassi <ebassi src gnome org>]

commit f7c3a0267aeae74a216de9f081b2cb189388ad88
Author: Leonardo Sandoval <leonardo sandoval gonzalez linux intel com>
Date:   Fri Sep 22 16:05:41 2017 -0700

    qemurunner: print tail qemu log in case bootlog is empty
    
    There are cases where the 'while loop' waiting for login prompt fails
    and the bootlog variable does not get populated, thus use the the new
    qemurunner member (self.msg) which stores all output coming from the qemu
    process.
    
    [YOCTO #12113]
    
    (From OE-Core rev: 39ffa0f3779305c5e8ef86fe4572e961c5912021)
    
    Signed-off-by: Leonardo Sandoval <leonardo sandoval gonzalez linux intel com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/lib/oeqa/utils/qemurunner.py |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/meta/lib/oeqa/utils/qemurunner.py b/meta/lib/oeqa/utils/qemurunner.py
index 427ae23..6bae388 100644
--- a/meta/lib/oeqa/utils/qemurunner.py
+++ b/meta/lib/oeqa/utils/qemurunner.py
@@ -51,6 +51,7 @@ class QemuRunner:
         self.logged = False
         self.thread = None
         self.use_kvm = use_kvm
+        self.msg = ''
 
         self.runqemutime = 120
         self.qemu_pidfile = 'pidfile_'+str(os.getpid())
@@ -79,6 +80,7 @@ class QemuRunner:
             # because is possible to have control characters
             msg = msg.decode("utf-8", errors='ignore')
             msg = re_control_char.sub('', msg)
+            self.msg += msg
             with codecs.open(self.logfile, "a", encoding="utf-8") as f:
                 f.write("%s" % msg)
 
@@ -307,9 +309,12 @@ class QemuRunner:
                         sock.close()
                         stopread = True
 
+
         if not reachedlogin:
             self.logger.info("Target didn't reached login boot in %d seconds" % self.boottime)
-            lines = "\n".join(bootlog.splitlines()[-25:])
+            tail = lambda l: "\n".join(l.splitlines()[-25:])
+            # in case bootlog is empty, use tail qemu log store at self.msg
+            lines = tail(bootlog if bootlog else self.msg)
             self.logger.info("Last 25 lines of text:\n%s" % lines)
             self.logger.info("Check full boot log: %s" % self.logfile)
             self._dump_host()