[OE-core] [PATCH 3/4] devpyshell: python3: flush stdout explicitly

[Ed Bartosh]

Opening text sream in unbuffered mode raises the following
exception In Python 3:
    ValueError: can't have unbuffered text I/O

Fixed by leaving std* streams in text mode and flushing
stdout explicitly.

Signed-off-by: Ed Bartosh <ed.bartosh at linux.intel.com>
---
 meta/classes/devshell.bbclass    | 2 ++
 scripts/oepydevshell-internal.py | 4 +---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/meta/classes/devshell.bbclass b/meta/classes/devshell.bbclass
index ce76ffe..be71aff 100644
--- a/meta/classes/devshell.bbclass
+++ b/meta/classes/devshell.bbclass
@@ -90,6 +90,7 @@ def devpyshell(d):
             else:
                 prompt = ps1
             sys.stdout.write(prompt)
+            sys.stdout.flush()
 
         # Restore Ctrl+C since bitbake masks this
         def signal_handler(signal, frame):
@@ -111,6 +112,7 @@ def devpyshell(d):
                         continue
                 except EOFError as e:
                     sys.stdout.write("\n")
+                    sys.stdout.flush()
                 except (OSError, IOError) as e:
                     if e.errno == 11:
                         continue
diff --git a/scripts/oepydevshell-internal.py b/scripts/oepydevshell-internal.py
index 7761f66..31a75ac 100755
--- a/scripts/oepydevshell-internal.py
+++ b/scripts/oepydevshell-internal.py
@@ -29,9 +29,6 @@ if len(sys.argv) != 3:
 pty = open(sys.argv[1], "w+b", 0)
 parent = int(sys.argv[2])
 
-# Don't buffer output by line endings
-sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)
-sys.stdin = os.fdopen(sys.stdin.fileno(), 'r', 0)
 nonblockingfd(pty)
 nonblockingfd(sys.stdin)
 
@@ -64,6 +61,7 @@ try:
                     # Write a page at a time to avoid overflowing output 
                     # d.keys() is a good way to do that
                     sys.stdout.write(i[:4096])
+                    sys.stdout.flush()
                     i = i[4096:]
                 if sys.stdin in ready:
                     echonocbreak(sys.stdin.fileno())
-- 
2.1.4