Fix test, update docs.

doc/breaking_changes.rst

@@ -8,6 +8,19 @@ Breaking changes
 6.0.0
 -----
 
+API/behaviour changes
+~~~~~~~~~~~~~~~~~~~~~
+
+In heyoka 6.0.0, the array of parameter values passed to the constructor
+of a Taylor integrator must either be empty (in which case the parameter
+values will be zero-inited), or it must have the correct size.
+
+In previous versions, heyoka would pad with zeroes the array of parameter values
+if its size was less than the correct one.
+
+General
+~~~~~~~
+
 - Support for LLVM<15 has been dropped.
 
 .. _bchanges_4_0_0:

doc/changelog.rst

@@ -25,6 +25,12 @@ New
 Changes
 ~~~~~~~
 
+- **BREAKING**: the array of parameter values passed to the
+  constructor of a Taylor integrator must now either be empty
+  (in which case the parameter values will be zero-inited),
+  or have the correct size
+  (`#451 <https://github.com/bluescarni/heyoka/pull/451>`__).
+  This is a :ref:`breaking change <bchanges_6_0_0>`.
 - **BREAKING**: the minimum required LLVM version is now 15
   (`#444 <https://github.com/bluescarni/heyoka/pull/444>`__).
   This is a :ref:`breaking change <bchanges_6_0_0>`.

test/taylor_adaptive_batch.cpp

@@ -1283,7 +1283,7 @@ TEST_CASE("stream output")
             auto ta = taylor_adaptive_batch<fp_t>{{prime(x) = v - par[1], prime(v) = -9.8 * sin(x + par[0])},
                                                   {fp_t(0.), fp_t(0.01), fp_t(0.5), fp_t(0.51)},
                                                   2u,
-                                                  kw::pars = std::vector{fp_t(-1e-4), fp_t(-1.1e-4)}};
+                                                  kw::pars = std::vector{fp_t(-1e-4), fp_t(-1.1e-4), fp_t(0), fp_t(0)}};
 
             std::ostringstream oss;