(#140) Return error if one of the commands on pipes fails

Author: sergiomb2

patchview/patchview-wrapper

@@ -60,16 +60,37 @@ args, unknown = parser.parse_known_args()
 largs = vars(args).get("git_args")
 rargs = vars(args).get("patchview_args")
 
+patchview_cmd = ["patchview"] + rargs + unknown
+pipetoview = False
 if tool_cmd.endswith("view"):
     # pipeline: first_pipe | second_pipe | editor
     tool_cmd = tool_cmd[:-4]  # remove "view"
-    git_cmd = [tool, tool_cmd] + largs
     patchview_cmd = ["filterdiff"] + rargs + unknown
-
-    p1 = Popen(git_cmd, stdout=PIPE, env=enviro, cwd='.')
-    p2 = Popen(patchview_cmd, stdin=p1.stdout, stdout=PIPE, env=enviro, cwd=workdir)
-    p1.stdout.close()
-
+    pipetoview = True
+git_cmd = [tool, tool_cmd] + largs
+
+p1 = Popen(git_cmd, stdout=PIPE, env=enviro, cwd=workdir)
+p2 = Popen(patchview_cmd, stdin=p1.stdout, stdout=PIPE, env=enviro, cwd=workdir)
+
+p1.wait()
+stdout1, stderr1 = p1.communicate()
+if p1.returncode != 0:
+    if stdout1:
+        sys.stdout.buffer.write(stdout1)
+    if stderr1:
+        sys.stderr.buffer.write(stderr1)
+    sys.exit(p1.returncode)
+
+p2.wait()
+stdout2, stderr2 = p2.communicate()
+if p2.returncode != 0:
+    if stdout2:
+        sys.stdout.buffer.write(stdout2)
+    if stderr2:
+        sys.stderr.buffer.write(stderr2)
+    sys.exit(p2.returncode)
+
+if pipetoview:
     dest_cmd = [editor, "-R", "-"]
     p3 = Popen(dest_cmd, stdin=PIPE)
     if args.debug:
@@ -79,26 +100,14 @@ if tool_cmd.endswith("view"):
         p3.stdin.write(debug_str.encode())
         p3.stdin.flush()
 
-    for chunk in iter(lambda: p2.stdout.read(4096), b''):
-        p3.stdin.write(chunk)
-        p3.stdin.flush()
-
-    p2.stdout.close()
+    p3.stdin.write(stdout2)
     p3.stdin.close()
     p3.wait()
 else:
-    # pipeline normal: tool cmd | patchview
-    git_cmd = [tool, tool_cmd] + largs
-    patchview_cmd = ["patchview"] + rargs + unknown
-
-    p1 = Popen(git_cmd, stdout=PIPE, env=os.environ, cwd='.')
-    p2 = Popen(patchview_cmd, stdin=p1.stdout, stdout=PIPE, env=enviro, cwd=workdir)
-    p1.stdout.close()
-
     # debug print
     if args.debug:
         print("%s | %s" % (" ".join(git_cmd), " ".join(patchview_cmd)))
         sys.stdout.flush()
 
-    sys.stdout.buffer.write(p2.communicate()[0])
+    sys.stdout.buffer.write(stdout2)