python: convenience methods for handler types

Author: yoff

python/ql/lib/semmle/python/Stmts.qll

@@ -392,6 +392,12 @@ class Try extends Try_ {
   /** Gets an exception handler of this try statement. */
   override Stmt getAHandler() { result = Try_.super.getAHandler() }
 
+  /** Gets a normal exception handler, `except`, of this try statement. */
+  ExceptStmt getANormalHandler() { result = this.getAHandler() }
+
+  /** Gets a group exception handler, `except*`, of this try statement. */
+  ExceptGroupStmt getAGroupHandler() { result = this.getAHandler() }
+
   override Stmt getLastStatement() {
     result = this.getFinalbody().getLastItem().getLastStatement()
     or

python/ql/src/Exceptions/UnguardedNextInGenerator.ql

@@ -52,7 +52,7 @@ predicate iter_not_exhausted(EssaVariable iterator) {
 predicate stop_iteration_handled(CallNode call) {
   exists(Try t |
     t.containsInScope(call.getNode()) and
-    t.getAHandler().getType() = stopIteration().getAValueReachableFromSource().asExpr()
+    t.getANormalHandler().getType() = stopIteration().getAValueReachableFromSource().asExpr()
   )
 }