Merge ~kissiel/checkbox-support:fix-1741217-broken-pipe-fwts into checkbox-support:master

[Maciej Kisielewski]

Fixes broken pipe that occurs on Artful in FWTS.

Somehow on artful zenity terminates before we flush it. I recon it has something to do with the DISPLAY being not available somehow in the middle of the test...

This fix doesn't really cure that situation, but handles symptoms (broken pipe traceback) gracefully.

To test it follow bug report and do what Taihsiang did.

[Jonathan Cave (jocave)]

LGTM +1

review: Approve

diff --git a/checkbox_support/scripts/fwts_test.py b/checkbox_support/scripts/fwts_test.py
index d4289df..c6e9963 100644
--- a/checkbox_support/scripts/fwts_test.py
+++ b/checkbox_support/scripts/fwts_test.py
@@ -336,7 +336,10 @@ def main():
                         progress_string).encode('utf-8'))
                     progress_indicator.stdin.write("{}\n".format(
                         progress_pct).encode('utf-8'))
-                    progress_indicator.stdin.flush()
+                    if progress_indicator.poll() is None:
+                        # LP: #1741217 process may have already terminated
+                        # flushing its stdin would yield broken pipe
+                        progress_indicator.stdin.flush()
                 elif "dialog" in detect_progress_indicator():
                     progress_indicator.stdin.write("XXX\n".encode('utf-8'))
                     progress_indicator.stdin.write(
@@ -347,7 +350,8 @@ def main():
                         progress_string.encode('utf-8'))
                     progress_indicator.stdin.write(
                         "\nXXX\n".encode('utf-8'))
-                    progress_indicator.stdin.flush()
+                    if progress_indicator.poll() is None:
+                        progress_indicator.stdin.flush()
                 else:
                     print(progress_string)
         if detect_progress_indicator():