lib/oe/utils: add eol to format_pkg_list()

Append '\n' to the non-empty formatted string before return. If you
write it to the (manifest) file, it will ensure file ends with a newline.

Many GNU utilities have problems processing the last line of a file
if it is not '\n' terminated. E.g. if the last line is not terminated
by a newline character, then "read" will read it but return false,
leaving the broken partial line in the read variable(s).
It can also break or adversely affect some text processing tools,
that operate on the file.

(From OE-Core rev: ee4d0c879713ba50dc6cc3300f44647faebee2e0)

Signed-off-by: grygorii tertychnyi <gtertych@cisco.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/rootfs-postcommands.bbclass

@@ -253,7 +253,6 @@ python write_image_manifest () {
     pkgs = image_list_installed_packages(d)
     with open(manifest_name, 'w+') as image_manifest:
         image_manifest.write(format_pkg_list(pkgs, "ver"))
-        image_manifest.write("\n")
 
     if os.path.exists(manifest_name):
         manifest_link = deploy_dir + "/" + link_name + ".manifest"

meta/lib/oe/utils.py

@@ -347,7 +347,13 @@ def format_pkg_list(pkg_dict, ret_format=None):
         for pkg in sorted(pkg_dict):
             output.append(pkg)
 
-    return '\n'.join(output)
+    output_str = '\n'.join(output)
+
+    if output_str:
+        # make sure last line is newline terminated
+        output_str += '\n'
+
+    return output_str
 
 def host_gcc_version(d, taskcontextonly=False):
     import re, subprocess