Make openLocked always return BlockingIOError on fail

src/Test/TestHelper.py

@@ -68,7 +68,7 @@ class TestHelper:
     def testOpenLocked(self):
         locked_f = helper.openLocked(config.data_dir + "/locked.file")
         assert locked_f
-        with pytest.raises(PermissionError):
+        with pytest.raises(BlockingIOError):
             locked_f_again = helper.openLocked(config.data_dir + "/locked.file")
         locked_f_different = helper.openLocked(config.data_dir + "/locked_different.file")
 

src/main.py

@@ -39,7 +39,7 @@ if config.action == "main":
     try:
         lock = helper.openLocked("%s/lock.pid" % config.data_dir, "w")
         lock.write("%s" % os.getpid())
-    except IOError as err:
+    except BlockingIOError as err:
         print("Can't open lock file, your ZeroNet client is probably already running, exiting... (%s)" % err)
         if config.open_browser and config.open_browser != "False":
             print("Opening browser: %s...", config.open_browser)

src/util/helper.py

@@ -37,16 +37,19 @@ def atomicWrite(dest, content, mode="wb"):
 
 
 def openLocked(path, mode="wb"):
-    if os.name == "posix":
-        import fcntl
-        f = open(path, mode)
-        fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
-    elif os.name == "nt":
-        import msvcrt
-        f = open(path, mode)
-        msvcrt.locking(f.fileno(), msvcrt.LK_NBLCK, 1)
-    else:
-        f = open(path, mode)
+    try:
+        if os.name == "posix":
+            import fcntl
+            f = open(path, mode)
+            fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
+        elif os.name == "nt":
+            import msvcrt
+            f = open(path, mode)
+            msvcrt.locking(f.fileno(), msvcrt.LK_NBLCK, 1)
+        else:
+            f = open(path, mode)
+    except (IOError, PermissionError, BlockingIOError) as err:
+        raise BlockingIOError("Unable to lock file: %s" % err)
     return f