Animation: Expand unit tests for `BKE_fcurve_active_keyframe_index()`

Expand unit test for `BKE_fcurve_active_keyframe_index()` to test edge
cases better.

This also introduces a new test macro `EXPECT_BLI_ASSERT()`, which can be
used to test that an assertion fails successfully.

No functional changes to actual Blender code.

intern/guardedalloc/tests/guardedalloc_overflow_test.cc

@@ -5,11 +5,6 @@
 #include "MEM_guardedalloc.h"
 
 /* We expect to abort on integer overflow, to prevent possible exploits. */
-#ifdef _WIN32
-#  define ABORT_PREDICATE ::testing::ExitedWithCode(3)
-#else
-#  define ABORT_PREDICATE ::testing::KilledBySignal(SIGABRT)
-#endif
 
 #if defined(__GNUC__) && !defined(__clang__)
 /* Disable since it's the purpose of this test. */

source/blender/blenkernel/intern/fcurve.c

@@ -855,7 +855,7 @@ void BKE_fcurve_active_keyframe_set(FCurve *fcu, const BezTriple *active_bezt)
   }
 
   /* The active keyframe should always be selected. */
-  BLI_assert(BEZT_ISSEL_ANY(active_bezt));
+  BLI_assert(BEZT_ISSEL_ANY(active_bezt) || !"active keyframe must be selected");
 
   fcu->active_keyframe_index = (int)offset;
 }

source/blender/blenkernel/intern/fcurve_test.cc

@@ -22,6 +22,7 @@
 #include "BKE_fcurve.h"
 
 #include "ED_keyframing.h"
+#include "ED_types.h" /* For SELECT. */
 
 #include "DNA_anim_types.h"
 
@@ -295,17 +296,38 @@ TEST(fcurve_active_keyframe, ActiveKeyframe)
   EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), FCURVE_ACTIVE_KEYFRAME_NONE);
 
   /* Check a "normal" action. */
+  fcu->bezt[2].f2 |= SELECT;
   BKE_fcurve_active_keyframe_set(fcu, &fcu->bezt[2]);
   EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), 2);
 
-  /* Check out of bounds. */
-  BKE_fcurve_active_keyframe_set(fcu, fcu->bezt - 20);
+  /* Check setting an unselected keyframe as active. */
+  fcu->bezt[2].f1 = fcu->bezt[2].f2 = fcu->bezt[2].f3 = 0;
+  EXPECT_BLI_ASSERT(BKE_fcurve_active_keyframe_set(fcu, &fcu->bezt[2]),
+                    "active keyframe must be selected");
   EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), FCURVE_ACTIVE_KEYFRAME_NONE);
 
-  /* Check out of bounds again. */
-  BKE_fcurve_active_keyframe_set(fcu, fcu->bezt + 4);
+  /* Check out of bounds (lower). */
+  BKE_fcurve_active_keyframe_set(fcu, fcu->bezt - 20);
+  EXPECT_EQ(fcu->active_keyframe_index, FCURVE_ACTIVE_KEYFRAME_NONE)
+      << "Setting out-of-bounds value via the API should result in valid active_keyframe_index";
   EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), FCURVE_ACTIVE_KEYFRAME_NONE);
 
+  fcu->active_keyframe_index = -20;
+  EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), FCURVE_ACTIVE_KEYFRAME_NONE)
+      << "Even with active_keyframe_index out of bounds, getting it via the API should produce a "
+         "valid value";
+
+  /* Check out of bounds (higher). */
+  BKE_fcurve_active_keyframe_set(fcu, fcu->bezt + 4);
+  EXPECT_EQ(fcu->active_keyframe_index, FCURVE_ACTIVE_KEYFRAME_NONE)
+      << "Setting out-of-bounds value via the API should result in valid active_keyframe_index";
+  EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), FCURVE_ACTIVE_KEYFRAME_NONE);
+
+  fcu->active_keyframe_index = fcu->totvert;
+  EXPECT_EQ(BKE_fcurve_active_keyframe_index(fcu), FCURVE_ACTIVE_KEYFRAME_NONE)
+      << "Even with active_keyframe_index out of bounds, getting it via the API should produce a "
+         "valid value";
+
   BKE_fcurve_free(fcu);
 }
 

tests/gtests/testing/testing.h

@@ -137,4 +137,22 @@ inline void EXPECT_EQ_ARRAY_ND(const T *expected, const T *actual, const size_t
   }
 }
 
+#ifdef _WIN32
+#  define ABORT_PREDICATE ::testing::ExitedWithCode(3)
+#else
+#  define ABORT_PREDICATE ::testing::KilledBySignal(SIGABRT)
+#endif
+
+/* Test macro for when BLI_assert() is expected to fail.
+ * Note that the EXPECT_BLI_ASSERT macro is a no-op, unless used in a debug build with
+ * WITH_ASSERT_ABORT=ON. */
+#if defined(WITH_ASSERT_ABORT) && !defined(NDEBUG)
+/* EXPECT_EXIT() is used as that's the only exit-expecting function in GTest that allows us to
+ * check for SIGABRT. */
+#  define EXPECT_BLI_ASSERT(function_call, expect_message) \
+    EXPECT_EXIT(function_call, ABORT_PREDICATE, expect_message)
+#else
+#  define EXPECT_BLI_ASSERT(function_call, expect_message) function_call
+#endif
+
 #endif  // __BLENDER_TESTING_H__