refactor stock ledger to be thread safe

stock/stock_ledger.py

@@ -10,7 +10,9 @@ import json
 # future reposting
 class NegativeStockError(webnotes.ValidationError): pass
 
-_exceptions = []
+_exceptions = webnotes.local('stockledger_exceptions')
+
+# _exceptions = []
 def update_entries_after(args, verbose=1):
 	"""
 		update valution rate and qty after transaction 
@@ -23,8 +25,8 @@ def update_entries_after(args, verbose=1):
 			"posting_time": "12:00"
 		}
 	"""
-	global _exceptions
-	_exceptions = []
+	if not _exceptions:
+		webnotes.local.stockledger_exceptions = []
 	
 	previous_sle = get_sle_before_datetime(args)
 	
@@ -141,9 +143,11 @@ def validate_negative_stock(qty_after_transaction, sle):
 	"""
 	diff = qty_after_transaction + flt(sle.actual_qty)
 
+	if not _exceptions:
+		webnotes.local.stockledger_exceptions = []
+	
 	if diff < 0 and abs(diff) > 0.0001:
 		# negative stock!
-		global _exceptions
 		exc = sle.copy().update({"diff": diff})
 		_exceptions.append(exc)
 		return False