Fixes and more tests

python · JukkaL · Apr 1, 2026 · Apr 1, 2026 · Apr 1, 2026 · Apr 1, 2026
commit 1d068f761e05f55135520dcbeb6ccfb3bb1444fa
diff --git a/mypyc/lib-rt/vecs/vec_nested.c b/mypyc/lib-rt/vecs/vec_nested.c
@@ -65,6 +65,10 @@ VecNested VecNested_ConvertFromNested(VecNestedBufItem item) {
 }
 
 VecNested VecNested_New(Py_ssize_t size, Py_ssize_t cap, size_t item_type, size_t depth) {
+    if (cap < 0) {
+        PyErr_SetString(PyExc_ValueError, "capacity must not be negative");
+        return vec_error();
+    }
     if (cap < size)
         cap = size;
     VecNested vec = vec_alloc(cap, item_type, depth);

diff --git a/mypyc/lib-rt/vecs/vec_t.c b/mypyc/lib-rt/vecs/vec_t.c
@@ -81,6 +81,10 @@ VecT VecT_ConvertFromNested(VecNestedBufItem item) {
 }
 
 VecT VecT_New(Py_ssize_t size, Py_ssize_t cap, size_t item_type) {
+    if (cap < 0) {
+        PyErr_SetString(PyExc_ValueError, "capacity must not be negative");
+        return vec_error();
+    }
     if (cap < size)
         cap = size;
     VecT vec = vec_alloc(cap, item_type);

diff --git a/mypyc/lib-rt/vecs/vec_template.c b/mypyc/lib-rt/vecs/vec_template.c
@@ -84,8 +84,12 @@ VEC FUNC(ConvertFromNested)(VecNestedBufItem item) {
 }
 
 VEC FUNC(New)(Py_ssize_t size, Py_ssize_t cap) {
+    if (cap < 0) {
+        PyErr_SetString(PyExc_ValueError, "capacity must not be negative");
+        return vec_error();
+    }
     if (cap < size)
-        size = cap;
+        cap = size;
     VEC vec = vec_alloc(cap);
     if (VEC_IS_ERROR(vec))
         return vec;

diff --git a/mypyc/test-data/irbuild-vec-i64.test b/mypyc/test-data/irbuild-vec-i64.test
@@ -872,4 +872,3 @@ L0:
     r4 = r3 + 8
     keep_alive r0
     return r0
-
diff --git a/mypyc/test-data/irbuild-vec-t.test b/mypyc/test-data/irbuild-vec-t.test
@@ -430,4 +430,3 @@ L0:
     r8 = r7 + 8
     keep_alive r4
     return r4
-
diff --git a/mypyc/test-data/run-vecs-i64.test b/mypyc/test-data/run-vecs-i64.test
@@ -512,3 +512,16 @@ def test_cap_buffer_reuse() -> None:
     v = append(v, 3)
     v[0] = 99
     assert old[0] == 99  # shared buffer
+
+def test_cap_below_initializer_length() -> None:
+    v = vec[i64]([10, 20, 30], capacity=1)
+    assert len(v) == 3
+    assert v[0] == 10
+    assert v[1] == 20
+    assert v[2] == 30
+
+def test_cap_negative() -> None:
+    with assertRaises(ValueError):
+        vec[i64](capacity=-1)
+    with assertRaises(ValueError):
+        vec[i64]([1], capacity=-1)
diff --git a/mypyc/test-data/run-vecs-nested.test b/mypyc/test-data/run-vecs-nested.test
@@ -542,3 +542,16 @@ def test_cap_buffer_reuse() -> None:
     v = append(v, vec[i64]([3]))
     v[0] = vec[i64]([99])
     assert old[0] == vec[i64]([99])  # shared buffer
+
+def test_cap_below_initializer_length() -> None:
+    v = vec[vec[i64]]([vec[i64]([10]), vec[i64]([20]), vec[i64]([30])], capacity=1)
+    assert len(v) == 3
+    assert v[0] == vec[i64]([10])
+    assert v[1] == vec[i64]([20])
+    assert v[2] == vec[i64]([30])
+
+def test_cap_negative() -> None:
+    with assertRaises(ValueError):
+        vec[vec[i64]](capacity=-1)
+    with assertRaises(ValueError):
+        vec[vec[i64]]([vec[i64]([1])], capacity=-1)
diff --git a/mypyc/test-data/run-vecs-t.test b/mypyc/test-data/run-vecs-t.test
@@ -472,3 +472,16 @@ def test_cap_buffer_reuse() -> None:
     v = append(v, 'c')
     v[0] = 'z'
     assert old[0] == 'z'  # shared buffer
+
+def test_cap_below_initializer_length() -> None:
+    v = vec[str](['a', 'b', 'c'], capacity=1)
+    assert len(v) == 3
+    assert v[0] == 'a'
+    assert v[1] == 'b'
+    assert v[2] == 'c'
+
+def test_cap_negative() -> None:
+    with assertRaises(ValueError):
+        vec[str](capacity=-1)
+    with assertRaises(ValueError):
+        vec[str](['x'], capacity=-1)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -872,4 +872,3 @@ L0:
		r4 = r3 + 8
		keep_alive r0
		return r0
Original file line number	Diff line number	Diff line change
Expand Up		@@ -430,4 +430,3 @@ L0:
		r8 = r7 + 8
		keep_alive r4
		return r4