[PATCH] buildhistory: fix latest_srcrev in the common case

[Christopher Larson <kergoth@gmail.com>]

From: Christopher Larson <chris_larson@mentor.com>

buildhistory was writing srcrevs.values() as SRCREV when only one
srcrev/branch exists. This returns a view of the dictionary values in python
3, and used to return a list in python 2, neither of which is an appropriate
value for SRCREV. It was resulting in latest_srcrev files like this:

    # SRCREV = "346584bf6e38232be8773c24fd7dedcbd7b3d9ed"
    SRCREV = "dict_values(['346584bf6e38232be8773c24fd7dedcbd7b3d9ed'])"

Which in turn would result in invalid output in buildhistory-collect-srcrevs.
Fix by calling `next(iter())` on the `.values()`

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
---
 meta/classes/buildhistory.bbclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/classes/buildhistory.bbclass b/meta/classes/buildhistory.bbclass
index 3a5bc2c..d82e9bb 100644
--- a/meta/classes/buildhistory.bbclass
+++ b/meta/classes/buildhistory.bbclass
@@ -833,7 +833,7 @@ python write_srcrev() {
                         f.write('# SRCREV_%s = "%s"\n' % (name, orig_srcrev))
                     f.write('SRCREV_%s = "%s"\n' % (name, srcrev))
             else:
-                f.write('SRCREV = "%s"\n' % srcrevs.values())
+                f.write('SRCREV = "%s"\n' % next(iter(srcrevs.values())))
             if len(tag_srcrevs) > 0:
                 for name, srcrev in tag_srcrevs.items():
                     f.write('# tag_%s = "%s"\n' % (name, srcrev))
-- 
2.8.0