Bug 1357238 - Allow apostrophes in try commit messages r=dustin

This copies the behavior of mozilla-taskcluster when it
submits try pushes. This will allow us to eventually stop
using mozilla-taskcluster.

MozReview-Commit-ID: J9zC92AE7HZ

taskcluster/taskgraph/try_option_syntax.py

@@ -194,20 +194,18 @@ def escape_whitespace_in_brackets(input_str):
     return result
 
 
-def find_try_idx(message):
+def split_try_msg(message):
+    try:
+        try_idx = message.index('try:')
+    except ValueError:
+        return []
+    message = message[try_idx:].split('\n')[0]
     # shlex used to ensure we split correctly when giving values to argparse.
-    parts = shlex.split(escape_whitespace_in_brackets(message))
-    try_idx = None
-    for idx, part in enumerate(parts):
-        if part == TRY_DELIMITER:
-            try_idx = idx
-            break
-
-    return try_idx, parts
+    return shlex.split(escape_whitespace_in_brackets(message))
 
 
 def parse_message(message):
-    try_idx, parts = find_try_idx(message)
+    parts = split_try_msg(message)
 
     # Argument parser based on try flag flags
     parser = argparse.ArgumentParser()
@@ -240,7 +238,6 @@ def parse_message(message):
 
     # In order to run test jobs multiple times
     parser.add_argument('--rebuild', dest='trigger_tests', type=int, default=1)
-    parts = parts[try_idx:] if try_idx is not None else []
     args, _ = parser.parse_known_args(parts)
     return args
 
@@ -290,8 +287,8 @@ class TryOptionSyntax(object):
         self.tag = None
         self.no_retry = False
 
-        try_idx, _ = find_try_idx(message)
-        if try_idx is None:
+        parts = split_try_msg(message)
+        if not parts:
             return None
 
         args = parse_message(message)