3 files changed, 72 insertions, 17 deletions

diff --git a/source/blender/blenkernel/BKE_nla.h b/source/blender/blenkernel/BKE_nla.h
index 9d3000759ab..efadd5c11d6 100644
--- a/source/blender/blenkernel/BKE_nla.h
+++ b/source/blender/blenkernel/BKE_nla.h
@@ -246,6 +246,24 @@ float BKE_nlastrip_compute_frame_from_previous_strip(struct NlaStrip *strip);
  */
 float BKE_nlastrip_compute_frame_to_next_strip(struct NlaStrip *strip);
 
+/**
+ * Returns the next strip in this strip's NLA track, or a null pointer.
+ *
+ * \param strip The strip to find the next trip from.
+ * \param check_transitions Whether or not to skip transitions.
+ * \return The next strip in the track, or NULL if none are present.
+ */
+struct NlaStrip *BKE_nlastrip_next_in_track(struct NlaStrip *strip, bool skip_transitions);
+
+/**
+ * Returns the previous strip in this strip's NLA track, or a null pointer.
+ *
+ * \param strip The strip to find the previous trip from.
+ * \param check_transitions Whether or not to skip transitions.
+ * \return The previous strip in the track, or NULL if none are present.
+ */
+struct NlaStrip *BKE_nlastrip_prev_in_track(struct NlaStrip *strip, bool skip_transitions);
+
 /* ............ */
 
 /**
diff --git a/source/blender/blenkernel/intern/nla.c b/source/blender/blenkernel/intern/nla.c
index fd3580a7e88..ba63cdff917 100644
--- a/source/blender/blenkernel/intern/nla.c
+++ b/source/blender/blenkernel/intern/nla.c
@@ -1272,6 +1272,34 @@ float BKE_nlastrip_compute_frame_to_next_strip(NlaStrip *strip)
   return limit_next;
 }
 
+NlaStrip *BKE_nlastrip_next_in_track(struct NlaStrip *strip, bool skip_transitions)
+{
+  NlaStrip *next = strip->next;
+  while (next != NULL) {
+    if (skip_transitions && (next->type & NLASTRIP_TYPE_TRANSITION)) {
+      next = next->next;
+    }
+    else {
+      return next;
+    }
+  }
+  return NULL;
+}
+
+NlaStrip *BKE_nlastrip_prev_in_track(struct NlaStrip *strip, bool skip_transitions)
+{
+  NlaStrip *prev = strip->prev;
+  while (prev != NULL) {
+    if (skip_transitions && (prev->type & NLASTRIP_TYPE_TRANSITION)) {
+      prev = prev->prev;
+    }
+    else {
+      return prev;
+    }
+  }
+  return NULL;
+}
+
 NlaStrip *BKE_nlastrip_find_active(NlaTrack *nlt)
 {
   if (nlt == NULL) {
diff --git a/source/blender/editors/transform/transform_convert_nla.c b/source/blender/editors/transform/transform_convert_nla.c
index cfa933d1600..af5a51cbff6 100644
--- a/source/blender/editors/transform/transform_convert_nla.c
+++ b/source/blender/editors/transform/transform_convert_nla.c
@@ -56,6 +56,29 @@ typedef struct TransDataNla {
 } TransDataNla;
 
 /* -------------------------------------------------------------------- */
+/** \name Transform application to NLA strips
+ * \{ */
+
+/**
+ * \brief Applies a translation to the given NlaStrip.
+ * \param strip_rna_ptr The RNA pointer of the NLA strip to modify.
+ * \param transdata The transformation info structure.
+ */
+static void applyTransformNLA_translation(PointerRNA *strip_rna_ptr, const TransDataNla *transdata)
+{
+  /* NOTE: we write these twice to avoid truncation errors which can arise when
+   * moving the strips a large distance using numeric input T33852.
+   */
+  RNA_float_set(strip_rna_ptr, "frame_start", transdata->h1[0]);
+  RNA_float_set(strip_rna_ptr, "frame_end", transdata->h2[0]);
+
+  RNA_float_set(strip_rna_ptr, "frame_start", transdata->h1[0]);
+  RNA_float_set(strip_rna_ptr, "frame_end", transdata->h2[0]);
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
 /** \name NLA Transform Creation
  * \{ */
 
@@ -329,15 +352,8 @@ static void recalcData_nla(TransInfo *t)
      *
      * this is done as a iterative procedure (done 5 times max for now)
      */
-    NlaStrip *prev = strip->prev;
-    while (prev != NULL && (prev->type & NLASTRIP_TYPE_TRANSITION)) {
-      prev = prev->prev;
-    }
-
-    NlaStrip *next = strip->next;
-    while (next != NULL && (next->type & NLASTRIP_TYPE_TRANSITION)) {
-      next = next->next;
-    }
+    NlaStrip *prev = BKE_nlastrip_prev_in_track(strip, true);
+    NlaStrip *next = BKE_nlastrip_next_in_track(strip, true);
 
     for (short iter = 0; iter < 5; iter++) {
       const bool pExceeded = (prev != NULL) && (tdn->h1[0] < prev->end);
@@ -380,17 +396,10 @@ static void recalcData_nla(TransInfo *t)
 
     /* Use RNA to write the values to ensure that constraints on these are obeyed
      * (e.g. for transition strips, the values are taken from the neighbors)
-     *
-     * NOTE: we write these twice to avoid truncation errors which can arise when
-     * moving the strips a large distance using numeric input T33852.
      */
     RNA_pointer_create(NULL, &RNA_NlaStrip, strip, &strip_ptr);
 
-    RNA_float_set(&strip_ptr, "frame_start", tdn->h1[0]);
-    RNA_float_set(&strip_ptr, "frame_end", tdn->h2[0]);
-
-    RNA_float_set(&strip_ptr, "frame_start", tdn->h1[0]);
-    RNA_float_set(&strip_ptr, "frame_end", tdn->h2[0]);
+    applyTransformNLA_translation(&strip_ptr, tdn);
 
     /* flush transforms to child strips (since this should be a meta) */
     BKE_nlameta_flush_transforms(strip);