Cleanup: keyframing return arguments

- Use 'int' for counters instead of short.
- Use 'bool' instead of a counter when only a change is being detected.
- Use typed enum for keying set flags.
- Include in comments when a negate error code may be returned.

8 files changed, 160 insertions, 139 deletions

diff --git a/source/blender/editors/animation/anim_channels_defines.c b/source/blender/editors/animation/anim_channels_defines.c
index 1af5721bffd..95165e35fd9 100644
--- a/source/blender/editors/animation/anim_channels_defines.c
+++ b/source/blender/editors/animation/anim_channels_defines.c
@@ -4357,7 +4357,7 @@ static void achannel_setting_slider_cb(bContext *C, void *id_poin, void *fcu_poi
   ListBase nla_cache = {NULL, NULL};
   PointerRNA id_ptr, ptr;
   PropertyRNA *prop;
-  short flag = 0;
+  eInsertKeyFlags flag = 0;
   bool done = false;
   float cfra;
 
@@ -4371,8 +4371,8 @@ static void achannel_setting_slider_cb(bContext *C, void *id_poin, void *fcu_poi
   /* get current frame and apply NLA-mapping to it (if applicable) */
   cfra = BKE_nla_tweakedit_remap(adt, (float)CFRA, NLATIME_CONVERT_UNMAP);
 
-  /* get flags for keyframing */
-  flag = ANIM_get_keyframing_flags(scene, 1);
+  /* Get flags for keyframing. */
+  flag = ANIM_get_keyframing_flags(scene, true);
 
   /* try to resolve the path stored in the F-Curve */
   if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop)) {
@@ -4411,7 +4411,7 @@ static void achannel_setting_slider_shapekey_cb(bContext *C, void *key_poin, voi
   ListBase nla_cache = {NULL, NULL};
   PointerRNA id_ptr, ptr;
   PropertyRNA *prop;
-  short flag = 0;
+  eInsertKeyFlags flag = 0;
   bool done = false;
   float cfra;
 
@@ -4426,7 +4426,7 @@ static void achannel_setting_slider_shapekey_cb(bContext *C, void *key_poin, voi
   cfra = BKE_nla_tweakedit_remap(key->adt, (float)CFRA, NLATIME_CONVERT_UNMAP);
 
   /* get flags for keyframing */
-  flag = ANIM_get_keyframing_flags(scene, 1);
+  flag = ANIM_get_keyframing_flags(scene, true);
 
   /* try to resolve the path stored in the F-Curve */
   if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop)) {
@@ -4472,7 +4472,7 @@ static void achannel_setting_slider_nla_curve_cb(bContext *C,
   ReportList *reports = CTX_wm_reports(C);
   Scene *scene = CTX_data_scene(C);
   ToolSettings *ts = scene->toolsettings;
-  short flag = 0;
+  eInsertKeyFlags flag = 0;
   bool done = false;
   float cfra;
 
@@ -4480,7 +4480,7 @@ static void achannel_setting_slider_nla_curve_cb(bContext *C,
   cfra = (float)CFRA;
 
   /* get flags for keyframing */
-  flag = ANIM_get_keyframing_flags(scene, 1);
+  flag = ANIM_get_keyframing_flags(scene, true);
 
   /* Get pointer and property from the slider -
    * this should all match up with the NlaStrip required. */
diff --git a/source/blender/editors/animation/drivers.c b/source/blender/editors/animation/drivers.c
index 64f7fe034dc..1af85e00045 100644
--- a/source/blender/editors/animation/drivers.c
+++ b/source/blender/editors/animation/drivers.c
@@ -421,7 +421,8 @@ int ANIM_add_driver_with_target(ReportList *reports,
 
 /* --------------------------------- */
 
-/* Main Driver Management API calls:
+/**
+ * Main Driver Management API calls:
  * Add a new driver for the specified property on the given ID block
  */
 int ANIM_add_driver(
@@ -1098,15 +1099,15 @@ static int add_driver_button_invoke(bContext *C, wmOperator *op, const wmEvent *
     /* 1) Create a new "empty" driver for this property */
     char *path = BKE_animdata_driver_path_hack(C, &ptr, prop, NULL);
     short flags = CREATEDRIVER_WITH_DEFAULT_DVAR;
-    short success = 0;
+    bool changed = false;
 
     if (path) {
-      success += ANIM_add_driver(
-          op->reports, ptr.owner_id, path, index, flags, DRIVER_TYPE_PYTHON);
+      changed |= (ANIM_add_driver(
+                      op->reports, ptr.owner_id, path, index, flags, DRIVER_TYPE_PYTHON) != 0);
       MEM_freeN(path);
     }
 
-    if (success) {
+    if (changed) {
       /* send updates */
       UI_context_update_anim_flag(C);
       DEG_id_tag_update(ptr.owner_id, ID_RECALC_COPY_ON_WRITE);
@@ -1144,7 +1145,7 @@ static int remove_driver_button_exec(bContext *C, wmOperator *op)
 {
   PointerRNA ptr = {NULL};
   PropertyRNA *prop = NULL;
-  short success = 0;
+  bool changed = false;
   int index;
   const bool all = RNA_boolean_get(op->ptr, "all");
 
@@ -1159,20 +1160,20 @@ static int remove_driver_button_exec(bContext *C, wmOperator *op)
     char *path = BKE_animdata_driver_path_hack(C, &ptr, prop, NULL);
 
     if (path) {
-      success = ANIM_remove_driver(op->reports, ptr.owner_id, path, index, 0);
+      changed = ANIM_remove_driver(op->reports, ptr.owner_id, path, index, 0);
 
       MEM_freeN(path);
     }
   }
 
-  if (success) {
+  if (changed) {
     /* send updates */
     UI_context_update_anim_flag(C);
     DEG_relations_tag_update(CTX_data_main(C));
     WM_event_add_notifier(C, NC_ANIMATION | ND_FCURVES_ORDER, NULL);  // XXX
   }
 
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_driver_button_remove(wmOperatorType *ot)
@@ -1234,7 +1235,7 @@ static int copy_driver_button_exec(bContext *C, wmOperator *op)
 {
   PointerRNA ptr = {NULL};
   PropertyRNA *prop = NULL;
-  short success = 0;
+  bool changed = false;
   int index;
 
   /* try to create driver using property retrieved from UI */
@@ -1245,7 +1246,7 @@ static int copy_driver_button_exec(bContext *C, wmOperator *op)
 
     if (path) {
       /* only copy the driver for the button that this was involved for */
-      success = ANIM_copy_driver(op->reports, ptr.owner_id, path, index, 0);
+      changed = ANIM_copy_driver(op->reports, ptr.owner_id, path, index, 0);
 
       UI_context_update_anim_flag(C);
 
@@ -1254,7 +1255,7 @@ static int copy_driver_button_exec(bContext *C, wmOperator *op)
   }
 
   /* since we're just copying, we don't really need to do anything else...*/
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_copy_driver_button(wmOperatorType *ot)
@@ -1278,7 +1279,7 @@ static int paste_driver_button_exec(bContext *C, wmOperator *op)
 {
   PointerRNA ptr = {NULL};
   PropertyRNA *prop = NULL;
-  short success = 0;
+  bool changed = false;
   int index;
 
   /* try to create driver using property retrieved from UI */
@@ -1289,7 +1290,7 @@ static int paste_driver_button_exec(bContext *C, wmOperator *op)
 
     if (path) {
       /* only copy the driver for the button that this was involved for */
-      success = ANIM_paste_driver(op->reports, ptr.owner_id, path, index, 0);
+      changed = ANIM_paste_driver(op->reports, ptr.owner_id, path, index, 0);
 
       UI_context_update_anim_flag(C);
 
@@ -1304,7 +1305,7 @@ static int paste_driver_button_exec(bContext *C, wmOperator *op)
   }
 
   /* since we're just copying, we don't really need to do anything else...*/
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_paste_driver_button(wmOperatorType *ot)
diff --git a/source/blender/editors/animation/keyframing.c b/source/blender/editors/animation/keyframing.c
index c8ef4fe2965..c80cfd77cf4 100644
--- a/source/blender/editors/animation/keyframing.c
+++ b/source/blender/editors/animation/keyframing.c
@@ -87,7 +87,7 @@ static KeyingSet *keyingset_get_from_op_with_error(wmOperator *op,
 /* Keyframing Setting Wrangling */
 
 /* Get the active settings for keyframing settings from context (specifically the given scene) */
-short ANIM_get_keyframing_flags(Scene *scene, short incl_mode)
+eInsertKeyFlags ANIM_get_keyframing_flags(Scene *scene, const bool use_autokey_mode)
 {
   eInsertKeyFlags flag = INSERTKEY_NOFLAGS;
 
@@ -110,7 +110,7 @@ short ANIM_get_keyframing_flags(Scene *scene, short incl_mode)
   }
 
   /* only if including settings from the autokeying mode... */
-  if (incl_mode) {
+  if (use_autokey_mode) {
     /* keyframing mode - only replace existing keyframes */
     if (IS_AUTOKEY_MODE(scene, EDITKEYS)) {
       flag |= INSERTKEY_REPLACE;
@@ -1328,7 +1328,9 @@ static bool insert_keyframe_fcurve_value(Main *bmain,
   }
 }
 
-/* Main Keyframing API call:
+/**
+ * Main Keyframing API call
+ *
  * Use this when validation of necessary animation data is necessary, since it may not exist yet.
  *
  * The flag argument is used for special settings that alter the behavior of
@@ -1336,18 +1338,20 @@ static bool insert_keyframe_fcurve_value(Main *bmain,
  * and extra keyframe filtering.
  *
  * index of -1 keys all array indices
+ *
+ * \return The number of key-frames inserted.
  */
-short insert_keyframe(Main *bmain,
-                      ReportList *reports,
-                      ID *id,
-                      bAction *act,
-                      const char group[],
-                      const char rna_path[],
-                      int array_index,
-                      float cfra,
-                      eBezTriple_KeyframeType keytype,
-                      ListBase *nla_cache,
-                      eInsertKeyFlags flag)
+int insert_keyframe(Main *bmain,
+                    ReportList *reports,
+                    ID *id,
+                    bAction *act,
+                    const char group[],
+                    const char rna_path[],
+                    int array_index,
+                    float cfra,
+                    eBezTriple_KeyframeType keytype,
+                    ListBase *nla_cache,
+                    eInsertKeyFlags flag)
 {
   PointerRNA id_ptr, ptr;
   PropertyRNA *prop = NULL;
@@ -1570,13 +1574,16 @@ static void deg_tag_after_keyframe_delete(Main *bmain, ID *id, AnimData *adt)
   }
 }
 
-short delete_keyframe(Main *bmain,
-                      ReportList *reports,
-                      ID *id,
-                      bAction *act,
-                      const char rna_path[],
-                      int array_index,
-                      float cfra)
+/**
+ * \return The number of key-frames deleted.
+ */
+int delete_keyframe(Main *bmain,
+                    ReportList *reports,
+                    ID *id,
+                    bAction *act,
+                    const char rna_path[],
+                    int array_index,
+                    float cfra)
 {
   AnimData *adt = BKE_animdata_from_id(id);
   PointerRNA id_ptr, ptr;
@@ -1667,20 +1674,23 @@ short delete_keyframe(Main *bmain,
 /* ************************************************** */
 /* KEYFRAME CLEAR */
 
-/* Main Keyframing API call:
+/**
+ * Main Keyframing API call:
  * Use this when validation of necessary animation data isn't necessary as it
  * already exists. It will clear the current buttons fcurve(s).
  *
  * The flag argument is used for special settings that alter the behavior of
  * the keyframe deletion. These include the quick refresh options.
+ *
+ * \return The number of f-curves removed.
  */
-static short clear_keyframe(Main *bmain,
-                            ReportList *reports,
-                            ID *id,
-                            bAction *act,
-                            const char rna_path[],
-                            int array_index,
-                            eInsertKeyFlags UNUSED(flag))
+static int clear_keyframe(Main *bmain,
+                          ReportList *reports,
+                          ID *id,
+                          bAction *act,
+                          const char rna_path[],
+                          int array_index,
+                          eInsertKeyFlags UNUSED(flag))
 {
   AnimData *adt = BKE_animdata_from_id(id);
   PointerRNA id_ptr, ptr;
@@ -1804,7 +1814,7 @@ static int insert_key_exec(bContext *C, wmOperator *op)
   bool ob_edit_mode = false;
 
   float cfra = (float)CFRA;  // XXX for now, don't bother about all the yucky offset crap
-  short success;
+  int success;
 
   KeyingSet *ks = keyingset_get_from_op_with_error(op, op->type->prop, scene);
   if (ks == NULL) {
@@ -2008,7 +2018,7 @@ static int delete_key_exec(bContext *C, wmOperator *op)
 {
   Scene *scene = CTX_data_scene(C);
   float cfra = (float)CFRA;  // XXX for now, don't bother about all the yucky offset crap
-  short success;
+  int success;
 
   KeyingSet *ks = keyingset_get_from_op_with_error(op, op->type->prop, scene);
   if (ks == NULL) {
@@ -2367,13 +2377,13 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
   char *path;
   uiBut *but;
   float cfra = (float)CFRA;
-  short success = 0;
+  bool changed = false;
   int index;
   const bool all = RNA_boolean_get(op->ptr, "all");
   eInsertKeyFlags flag = INSERTKEY_NOFLAGS;
 
   /* flags for inserting keyframes */
-  flag = ANIM_get_keyframing_flags(scene, 1);
+  flag = ANIM_get_keyframing_flags(scene, true);
 
   /* try to insert keyframe using property retrieved from UI */
   if (!(but = UI_context_active_but_prop_get(C, &ptr, &prop, &index))) {
@@ -2391,7 +2401,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
       FCurve *fcu = list_find_fcurve(&strip->fcurves, RNA_property_identifier(prop), index);
 
       if (fcu) {
-        success = insert_keyframe_direct(
+        changed = insert_keyframe_direct(
             op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, 0);
       }
       else {
@@ -2408,7 +2418,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
       fcu = rna_get_fcurve_context_ui(C, &ptr, prop, index, NULL, NULL, &driven, &special);
 
       if (fcu && driven) {
-        success = insert_keyframe_direct(
+        changed = insert_keyframe_direct(
             op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, INSERTKEY_DRIVER);
       }
     }
@@ -2445,17 +2455,17 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
           index = -1;
         }
 
-        success = insert_keyframe(bmain,
-                                  op->reports,
-                                  ptr.owner_id,
-                                  NULL,
-                                  group,
-                                  path,
-                                  index,
-                                  cfra,
-                                  ts->keyframe_type,
-                                  NULL,
-                                  flag);
+        changed = (insert_keyframe(bmain,
+                                   op->reports,
+                                   ptr.owner_id,
+                                   NULL,
+                                   group,
+                                   path,
+                                   index,
+                                   cfra,
+                                   ts->keyframe_type,
+                                   NULL,
+                                   flag) != 0);
 
         MEM_freeN(path);
       }
@@ -2484,7 +2494,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
     }
   }
 
-  if (success) {
+  if (changed) {
     ID *id = ptr.owner_id;
     AnimData *adt = BKE_animdata_from_id(id);
     if (adt->action != NULL) {
@@ -2499,7 +2509,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
     WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_ADDED, NULL);
   }
 
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_keyframe_insert_button(wmOperatorType *ot)
@@ -2530,7 +2540,7 @@ static int delete_key_button_exec(bContext *C, wmOperator *op)
   Main *bmain = CTX_data_main(C);
   char *path;
   float cfra = (float)CFRA;  // XXX for now, don't bother about all the yucky offset crap
-  short success = 0;
+  bool changed = false;
   int index;
   const bool all = RNA_boolean_get(op->ptr, "all");
 
@@ -2573,7 +2583,7 @@ static int delete_key_button_exec(bContext *C, wmOperator *op)
           if (found) {
             /* delete the key at the index (will sanity check + do recalc afterwards) */
             delete_fcurve_key(fcu, i, 1);
-            success = true;
+            changed = true;
           }
         }
       }
@@ -2588,7 +2598,7 @@ static int delete_key_button_exec(bContext *C, wmOperator *op)
           index = -1;
         }
 
-        success = delete_keyframe(bmain, op->reports, ptr.owner_id, NULL, path, index, cfra);
+        changed = delete_keyframe(bmain, op->reports, ptr.owner_id, NULL, path, index, cfra) != 0;
         MEM_freeN(path);
       }
       else if (G.debug & G_DEBUG) {
@@ -2600,7 +2610,7 @@ static int delete_key_button_exec(bContext *C, wmOperator *op)
     printf("ptr.data = %p, prop = %p\n", ptr.data, (void *)prop);
   }
 
-  if (success) {
+  if (changed) {
     /* send updates */
     UI_context_update_anim_flag(C);
 
@@ -2608,7 +2618,7 @@ static int delete_key_button_exec(bContext *C, wmOperator *op)
     WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_REMOVED, NULL);
   }
 
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_keyframe_delete_button(wmOperatorType *ot)
@@ -2637,7 +2647,7 @@ static int clear_key_button_exec(bContext *C, wmOperator *op)
   PropertyRNA *prop = NULL;
   Main *bmain = CTX_data_main(C);
   char *path;
-  short success = 0;
+  bool changed = false;
   int index;
   const bool all = RNA_boolean_get(op->ptr, "all");
 
@@ -2656,7 +2666,7 @@ static int clear_key_button_exec(bContext *C, wmOperator *op)
         index = -1;
       }
 
-      success += clear_keyframe(bmain, op->reports, ptr.owner_id, NULL, path, index, 0);
+      changed |= (clear_keyframe(bmain, op->reports, ptr.owner_id, NULL, path, index, 0) != 0);
       MEM_freeN(path);
     }
     else if (G.debug & G_DEBUG) {
@@ -2667,7 +2677,7 @@ static int clear_key_button_exec(bContext *C, wmOperator *op)
     printf("ptr.data = %p, prop = %p\n", ptr.data, (void *)prop);
   }
 
-  if (success) {
+  if (changed) {
     /* send updates */
     UI_context_update_anim_flag(C);
 
@@ -2675,7 +2685,7 @@ static int clear_key_button_exec(bContext *C, wmOperator *op)
     WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_REMOVED, NULL);
   }
 
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_keyframe_clear_button(wmOperatorType *ot)
@@ -3025,7 +3035,7 @@ bool ED_autokeyframe_property(
     if (autokeyframe_cfra_can_key(scene, id)) {
       ReportList *reports = CTX_wm_reports(C);
       ToolSettings *ts = scene->toolsettings;
-      short flag = ANIM_get_keyframing_flags(scene, 1);
+      const eInsertKeyFlags flag = ANIM_get_keyframing_flags(scene, true);
 
       /* Note: We use rnaindex instead of fcu->array_index,
        *       because a button may control all items of an array at once.
diff --git a/source/blender/editors/animation/keyingsets.c b/source/blender/editors/animation/keyingsets.c
index 6b33c100a8f..d2e542772c2 100644
--- a/source/blender/editors/animation/keyingsets.c
+++ b/source/blender/editors/animation/keyingsets.c
@@ -109,7 +109,8 @@ static bool keyingset_poll_activePath_edit(bContext *C)
 static int add_default_keyingset_exec(bContext *C, wmOperator *UNUSED(op))
 {
   Scene *scene = CTX_data_scene(C);
-  short flag = 0, keyingflag = 0;
+  eKS_Settings flag = 0;
+  eInsertKeyFlags keyingflag = 0;
 
   /* validate flags
    * - absolute KeyingSets should be created by default
@@ -117,7 +118,7 @@ static int add_default_keyingset_exec(bContext *C, wmOperator *UNUSED(op))
   flag |= KEYINGSET_ABSOLUTE;
 
   /* 2nd arg is 0 to indicate that we don't want to include autokeying mode related settings */
-  keyingflag = ANIM_get_keyframing_flags(scene, 0);
+  keyingflag = ANIM_get_keyframing_flags(scene, false);
 
   /* call the API func, and set the active keyingset index */
   BKE_keyingset_add(&scene->keyingsets, NULL, NULL, flag, keyingflag);
@@ -289,7 +290,7 @@ static int add_keyingset_button_exec(bContext *C, wmOperator *op)
   PropertyRNA *prop = NULL;
   PointerRNA ptr = {NULL};
   char *path = NULL;
-  short success = 0;
+  bool changed = false;
   int index = 0, pflag = 0;
   const bool all = RNA_boolean_get(op->ptr, "all");
 
@@ -304,14 +305,15 @@ static int add_keyingset_button_exec(bContext *C, wmOperator *op)
    * - add a new one if it doesn't exist
    */
   if (scene->active_keyingset == 0) {
-    short flag = 0, keyingflag = 0;
+    eKS_Settings flag = 0;
+    eInsertKeyFlags keyingflag = 0;
 
     /* validate flags
      * - absolute KeyingSets should be created by default
      */
     flag |= KEYINGSET_ABSOLUTE;
 
-    keyingflag |= ANIM_get_keyframing_flags(scene, 0);
+    keyingflag |= ANIM_get_keyframing_flags(scene, false);
 
     if (IS_AUTOKEY_FLAG(scene, XYZ2RGB)) {
       keyingflag |= INSERTKEY_XYZ2RGB;
@@ -350,14 +352,14 @@ static int add_keyingset_button_exec(bContext *C, wmOperator *op)
       /* add path to this setting */
       BKE_keyingset_add_path(ks, ptr.owner_id, NULL, path, index, pflag, KSP_GROUP_KSNAME);
       ks->active_path = BLI_listbase_count(&ks->paths);
-      success = 1;
+      changed = true;
 
       /* free the temp path created */
       MEM_freeN(path);
     }
   }
 
-  if (success) {
+  if (changed) {
     /* send updates */
     WM_event_add_notifier(C, NC_SCENE | ND_KEYINGSET, NULL);
 
@@ -365,7 +367,7 @@ static int add_keyingset_button_exec(bContext *C, wmOperator *op)
     BKE_reportf(op->reports, RPT_INFO, "Property added to Keying Set: '%s'", ks->name);
   }
 
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_keyingset_button_add(wmOperatorType *ot)
@@ -395,7 +397,7 @@ static int remove_keyingset_button_exec(bContext *C, wmOperator *op)
   PropertyRNA *prop = NULL;
   PointerRNA ptr = {NULL};
   char *path = NULL;
-  short success = 0;
+  bool changed = false;
   int index = 0;
 
   /* try to add to keyingset using property retrieved from UI */
@@ -431,7 +433,7 @@ static int remove_keyingset_button_exec(bContext *C, wmOperator *op)
 
       if (ksp) {
         BKE_keyingset_free_path(ks, ksp);
-        success = 1;
+        changed = true;
       }
 
       /* free temp path used */
@@ -439,7 +441,7 @@ static int remove_keyingset_button_exec(bContext *C, wmOperator *op)
     }
   }
 
-  if (success) {
+  if (changed) {
     /* send updates */
     WM_event_add_notifier(C, NC_SCENE | ND_KEYINGSET, NULL);
 
@@ -447,7 +449,7 @@ static int remove_keyingset_button_exec(bContext *C, wmOperator *op)
     BKE_report(op->reports, RPT_INFO, "Property removed from Keying Set");
   }
 
-  return (success) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
+  return (changed) ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void ANIM_OT_keyingset_button_remove(wmOperatorType *ot)
@@ -931,14 +933,15 @@ void ANIM_relative_keyingset_add_source(ListBase *dsources, ID *id, StructRNA *s
 
 /* KeyingSet Operations (Insert/Delete Keyframes) ------------ */
 
-/* Given a KeyingSet and context info, validate Keying Set's paths.
+/**
+ * Given a KeyingSet and context info, validate Keying Set's paths.
  * This is only really necessary with relative/built-in KeyingSets
  * where their list of paths is dynamically generated based on the
  * current context info.
  *
  * Returns 0 if succeeded, otherwise an error code: eModifyKey_Returns
  */
-short ANIM_validate_keyingset(bContext *C, ListBase *dsources, KeyingSet *ks)
+eModifyKey_Returns ANIM_validate_keyingset(bContext *C, ListBase *dsources, KeyingSet *ks)
 {
   /* sanity check */
   if (ks == NULL) {
@@ -990,12 +993,12 @@ short ANIM_validate_keyingset(bContext *C, ListBase *dsources, KeyingSet *ks)
 }
 
 /* Determine which keying flags apply based on the override flags */
-static short keyingset_apply_keying_flags(const short base_flags,
-                                          const short overrides,
-                                          const short own_flags)
+static eInsertKeyFlags keyingset_apply_keying_flags(const eInsertKeyFlags base_flags,
+                                                    const eInsertKeyFlags overrides,
+                                                    const eInsertKeyFlags own_flags)
 {
   /* Pass through all flags by default (i.e. even not explicitly listed ones). */
-  short result = base_flags;
+  eInsertKeyFlags result = base_flags;
 
   /* The logic for whether a keying flag applies is as follows:
    * - If the flag in question is set in "overrides", that means that the
@@ -1025,7 +1028,9 @@ static short keyingset_apply_keying_flags(const short base_flags,
  * Given a KeyingSet and context info (if required),
  * modify keyframes for the channels specified by the KeyingSet.
  * This takes into account many of the different combinations of using KeyingSets.
- * Returns the number of channels that keyframes were added to
+ *
+ * \returns the number of channels that key-frames were added or
+ * #eModifyKey_Returns (a negative number).
  */
 int ANIM_apply_keyingset(
     bContext *C, ListBase *dsources, bAction *act, KeyingSet *ks, short mode, float cfra)
@@ -1035,9 +1040,10 @@ int ANIM_apply_keyingset(
   ReportList *reports = CTX_wm_reports(C);
   KS_Path *ksp;
   ListBase nla_cache = {NULL, NULL};
-  const short base_kflags = ANIM_get_keyframing_flags(scene, 1);
+  const eInsertKeyFlags base_kflags = ANIM_get_keyframing_flags(scene, true);
   const char *groupname = NULL;
-  short kflag = 0, success = 0;
+  eInsertKeyFlags kflag = 0;
+  int success = 0;
   char keytype = scene->toolsettings->keyframe_type;
 
   /* sanity checks */
@@ -1055,17 +1061,19 @@ int ANIM_apply_keyingset(
   }
 
   /* if relative Keying Sets, poll and build up the paths */
-  success = ANIM_validate_keyingset(C, dsources, ks);
-
-  if (success != 0) {
-    /* return error code if failed */
-    return success;
+  {
+    const eModifyKey_Returns error = ANIM_validate_keyingset(C, dsources, ks);
+    if (error != 0) {
+      BLI_assert(error < 0);
+      /* return error code if failed */
+      return error;
+    }
   }
 
   /* apply the paths as specified in the KeyingSet now */
   for (ksp = ks->paths.first; ksp; ksp = ksp->next) {
     int arraylen, i;
-    short kflag2;
+    eInsertKeyFlags kflag2;
 
     /* skip path if no ID pointer is specified */
     if (ksp->id == NULL) {
diff --git a/source/blender/editors/include/ED_keyframing.h b/source/blender/editors/include/ED_keyframing.h
index 7baaaf63d6a..2f81e28b496 100644
--- a/source/blender/editors/include/ED_keyframing.h
+++ b/source/blender/editors/include/ED_keyframing.h
@@ -56,9 +56,9 @@ struct NlaKeyframingContext;
 /* ************ Keyframing Management **************** */
 
 /* Get the active settings for keyframing settings from context (specifically the given scene)
- * - incl_mode: include settings from keyframing mode in the result (i.e. replace only)
+ * - use_autokey_mode: include settings from keyframing mode in the result (i.e. replace only).
  */
-short ANIM_get_keyframing_flags(struct Scene *scene, short incl_mode);
+eInsertKeyFlags ANIM_get_keyframing_flags(struct Scene *scene, const bool use_autokey_mode);
 
 /* -------- */
 
@@ -129,28 +129,28 @@ bool insert_keyframe_direct(struct ReportList *reports,
  * Use this to create any necessary animation data, and then insert a keyframe
  * using the current value being keyframed, in the relevant place. Returns success.
  */
-short insert_keyframe(struct Main *bmain,
-                      struct ReportList *reports,
-                      struct ID *id,
-                      struct bAction *act,
-                      const char group[],
-                      const char rna_path[],
-                      int array_index,
-                      float cfra,
-                      eBezTriple_KeyframeType keytype,
-                      struct ListBase *nla_cache,
-                      eInsertKeyFlags flag);
+int insert_keyframe(struct Main *bmain,
+                    struct ReportList *reports,
+                    struct ID *id,
+                    struct bAction *act,
+                    const char group[],
+                    const char rna_path[],
+                    int array_index,
+                    float cfra,
+                    eBezTriple_KeyframeType keytype,
+                    struct ListBase *nla_cache,
+                    eInsertKeyFlags flag);
 
 /* Main Keyframing API call:
  * Use this to delete keyframe on current frame for relevant channel.
  * Will perform checks just in case. */
-short delete_keyframe(struct Main *bmain,
-                      struct ReportList *reports,
-                      struct ID *id,
-                      struct bAction *act,
-                      const char rna_path[],
-                      int array_index,
-                      float cfra);
+int delete_keyframe(struct Main *bmain,
+                    struct ReportList *reports,
+                    struct ID *id,
+                    struct bAction *act,
+                    const char rna_path[],
+                    int array_index,
+                    float cfra);
 
 /* ************ Keying Sets ********************** */
 
@@ -225,7 +225,9 @@ typedef enum eModifyKey_Returns {
 
 /* poll the current KeyingSet, updating it's set of paths
  * (if "builtin"/"relative") for context changes */
-short ANIM_validate_keyingset(struct bContext *C, ListBase *dsources, struct KeyingSet *ks);
+eModifyKey_Returns ANIM_validate_keyingset(struct bContext *C,
+                                           ListBase *dsources,
+                                           struct KeyingSet *ks);
 
 /* use the specified KeyingSet to add/remove various Keyframes on the specified frame */
 int ANIM_apply_keyingset(struct bContext *C,
diff --git a/source/blender/editors/space_action/action_edit.c b/source/blender/editors/space_action/action_edit.c
index 98e2bde499e..a1d8b9d0b2e 100644
--- a/source/blender/editors/space_action/action_edit.c
+++ b/source/blender/editors/space_action/action_edit.c
@@ -707,7 +707,7 @@ static void insert_action_keys(bAnimContext *ac, short mode)
   ReportList *reports = ac->reports;
   Scene *scene = ac->scene;
   ToolSettings *ts = scene->toolsettings;
-  short flag = 0;
+  eInsertKeyFlags flag;
 
   /* filter data */
   filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE |
@@ -721,8 +721,8 @@ static void insert_action_keys(bAnimContext *ac, short mode)
 
   ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
 
-  /* init keyframing flag */
-  flag = ANIM_get_keyframing_flags(scene, 1);
+  /* Init keyframing flag. */
+  flag = ANIM_get_keyframing_flags(scene, true);
 
   /* insert keyframes */
   for (ale = anim_data.first; ale; ale = ale->next) {
diff --git a/source/blender/editors/space_graph/graph_edit.c b/source/blender/editors/space_graph/graph_edit.c
index aea9308afdb..623d7e287d2 100644
--- a/source/blender/editors/space_graph/graph_edit.c
+++ b/source/blender/editors/space_graph/graph_edit.c
@@ -610,7 +610,7 @@ static void insert_graph_keys(bAnimContext *ac, eGraphKeys_InsertKey_Types mode)
   SpaceGraph *sipo = (SpaceGraph *)ac->sl;
   Scene *scene = ac->scene;
   ToolSettings *ts = scene->toolsettings;
-  short flag = 0;
+  eInsertKeyFlags flag = 0;
 
   /* filter data */
   filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_CURVE_VISIBLE | ANIMFILTER_FOREDIT |
@@ -639,8 +639,8 @@ static void insert_graph_keys(bAnimContext *ac, eGraphKeys_InsertKey_Types mode)
     return;
   }
 
-  /* init keyframing flag */
-  flag = ANIM_get_keyframing_flags(scene, 1);
+  /* Init key-framing flag. */
+  flag = ANIM_get_keyframing_flags(scene, true);
 
   /* insert keyframes */
   if (mode & GRAPHKEYS_INSERTKEY_CURSOR) {
diff --git a/source/blender/editors/transform/transform_convert.c b/source/blender/editors/transform/transform_convert.c
index 97a61ab9d9e..55f08d501ec 100644
--- a/source/blender/editors/transform/transform_convert.c
+++ b/source/blender/editors/transform/transform_convert.c
@@ -1424,10 +1424,10 @@ void autokeyframe_object(bContext *C, Scene *scene, ViewLayer *view_layer, Objec
     KeyingSet *active_ks = ANIM_scene_get_active_keyingset(scene);
     ListBase dsources = {NULL, NULL};
     float cfra = (float)CFRA;  // xxx this will do for now
-    short flag = 0;
+    eInsertKeyFlags flag = 0;
 
-    /* get flags used for inserting keyframes */
-    flag = ANIM_get_keyframing_flags(scene, 1);
+    /* Get flags used for inserting keyframes. */
+    flag = ANIM_get_keyframing_flags(scene, true);
 
     /* add datasource override for the object */
     ANIM_relative_keyingset_add_source(&dsources, id, NULL, NULL);
@@ -1566,14 +1566,14 @@ void autokeyframe_pose(bContext *C, Scene *scene, Object *ob, int tmode, short t
     KeyingSet *active_ks = ANIM_scene_get_active_keyingset(scene);
     ListBase nla_cache = {NULL, NULL};
     float cfra = (float)CFRA;
-    short flag = 0;
+    eInsertKeyFlags flag = 0;
 
     /* flag is initialized from UserPref keyframing settings
      * - special exception for targetless IK - INSERTKEY_MATRIX keyframes should get
      *   visual keyframes even if flag not set, as it's not that useful otherwise
      *   (for quick animation recording)
      */
-    flag = ANIM_get_keyframing_flags(scene, 1);
+    flag = ANIM_get_keyframing_flags(scene, true);
 
     if (targetless_ik) {
       flag |= INSERTKEY_MATRIX;