add sig_on and sig_off to avoid segfault

src/sage/modules/free_module_element.pyx

@@ -1920,15 +1920,20 @@
 
     def get(self, i):
         """
-        Like ``__getitem__`` but without bounds checking:
-        `i` must satisfy ``0 <= i < self.degree``.
+        Return the `i`-th entry of ``self``.
+
+        This is equivalent to ``self[i]``.
 
         EXAMPLES::
 
             sage: vector(SR, [1/2,2/5,0]).get(0)                                        # needs sage.symbolic
             1/2
+            sage: zero_vector(3).get(5)
+            Traceback (most recent call last):
+            ...
+            IndexError: vector index out of range
         """
-        return self.get_unsafe(i)
+        return self[i]
 
     def __setitem__(self, i, value):
         """
@@ -1982,19 +1987,23 @@
 
     def set(self, i, value):
         """
-        Like ``__setitem__`` but without type or bounds checking:
-        `i` must satisfy ``0 <= i < self.degree`` and ``value`` must be
-        an element of the coordinate ring.
+        Set the `i`-th entry of ``self`` to ``value``.
+
+        This is equivalent to ``self[i] = value``.
 
         EXAMPLES::
 
-            sage: v = vector(SR, [1/2,2/5,0]); v                                        # needs sage.symbolic
+            sage: # needs sage.symbolic
+            sage: v = vector(SR, [1/2,2/5,0]); v
             (1/2, 2/5, 0)
-            sage: v.set(2, pi); v                                                       # needs sage.symbolic
+            sage: v.set(2, pi); v
             (1/2, 2/5, pi)
+            sage: v.set(5, 1)
+            Traceback (most recent call last):
+            ...
+            IndexError: vector index out of range
         """
-        assert value.parent() is self.coordinate_ring()
-        self.set_unsafe(i, value)
+        self[i] = value
 
     def __invert__(self):
         """
@@ -5302,16 +5311,15 @@
         """
         EXAMPLES::
 
             sage: v = vector([-1,0,2/3,pi], sparse=True)                                # needs sage.symbolic
             sage: v.get(1)                                                              # needs sage.symbolic
             0
             sage: v.get(2)                                                              # needs sage.symbolic
             2/3
-
-        For this class, 0 is returned if the access is out of bounds::
-
             sage: v.get(10)                                                             # needs sage.symbolic
-            0
+            Traceback (most recent call last):
+            ...
+            IndexError: vector index out of range
         """
         try:
             return self._entries[i]
@@ -5336,7 +5344,7 @@
             ...
             TypeError: self must be a numeric expression
 
-        ::
+        TESTS::
 
             sage: # needs sage.symbolic
             sage: v = vector([1,2/3,pi], sparse=True)
@@ -5349,13 +5357,11 @@
 
         This assignment is illegal::
 
-            sage: v.set(10, pi)                                                         # needs sage.symbolic
-
-        This lack of bounds checking causes trouble later::
-
-            sage: v                                                                     # needs sage.symbolic
-            <repr(<sage.modules.free_module.FreeModule_ambient_field_with_category.element_class at 0x...>) failed:
-             IndexError: list assignment index out of range>
+            sage: # needs sage.symbolic
+            sage: v.set(10, pi)
+            Traceback (most recent call last):
+            ...
+            IndexError: vector index out of range
         """
         if value:
             self._entries[i] = value