Transpiler: fix pserver crash due to split var name check.

In notest_dist_label_semantic_roles.py, "emb" is matched with
"embedding_1.w_0", but they are two irrevalent vars.

Fixes: https://github.com/PaddlePaddle/Paddle/issues/7701

python/paddle/v2/fluid/distribute_transpiler.py

@@ -33,6 +33,10 @@ class VarBlock:
         return "%s:%d:%d" % (self.varname, self.offset, self.size)
 
 
+def same_or_split_var(p_name, var_name):
+    return p_name == var_name or p_name.startswith(var_name + ".block")
+
+
 def split_dense_variable(var_list,
                          pserver_count,
                          min_block_size=1024,
@@ -303,8 +307,8 @@ class DistributeTranspiler:
                 return True
             else:
                 for n in param_names:
-                    if n.startswith(op.inputs["Param"].name+".block") and \
-                       n != op.inputs["Param"].name:
+                    if same_or_split_var(n, op.inputs[
+                            "Param"].name) and n != op.inputs["Param"].name:
                         return True
                 return False
         else:
@@ -335,7 +339,7 @@ class DistributeTranspiler:
             if key == "Grad":
                 grad_block = None
                 for g in self.param_grad_ep_mapping[endpoint]["grads"]:
-                    if g.name.startswith(var.name):
+                    if same_or_split_var(g.name, var.name):
                         grad_block = g
                         break
                 if not grad_block:
@@ -365,7 +369,7 @@ class DistributeTranspiler:
                 # param is already created on global program
                 param_block = None
                 for p in self.param_grad_ep_mapping[endpoint]["params"]:
-                    if p.name.startswith(var.name):
+                    if same_or_split_var(p.name, var.name):
                         param_block = p
                         break
                 if not param_block:
@@ -502,7 +506,7 @@ class DistributeTranspiler:
         def _get_splited_name_and_shape(varname):
             for idx, splited_param in enumerate(params):
                 pname = splited_param.name
-                if pname.startswith(varname) and varname != pname:
+                if same_or_split_var(pname, varname) and varname != pname:
                     return pname, splited_param.shape
             return "", []