[Bf-blender-cvs] [f31ad5d98b3] master: Cleanup: refactoring BKE_nlastrips_add_strip method to Null check. Adding Unit tests for method

[Nate Rupsis]

Commit: f31ad5d98b3aa0697b5b1d477f7d58791ac19f97
Author: Nate Rupsis
Date:   Mon Jan 30 14:39:36 2023 -0500
Branches: master
https://developer.blender.org/rBf31ad5d98b3aa0697b5b1d477f7d58791ac19f97

Cleanup: refactoring BKE_nlastrips_add_strip method to Null check. Adding Unit tests for method

Reviewed By: Sybren

Differential Revision: https://developer.blender.org/D17155

===================================================================

M	source/blender/blenkernel/BKE_nla.h
M	source/blender/blenkernel/intern/nla.c
M	source/blender/blenkernel/intern/nla_test.cc
M	source/blender/makesrna/intern/rna_nla.c

===================================================================

diff --git a/source/blender/blenkernel/BKE_nla.h b/source/blender/blenkernel/BKE_nla.h
index dd558dc197c..d4d94618cc9 100644
--- a/source/blender/blenkernel/BKE_nla.h
+++ b/source/blender/blenkernel/BKE_nla.h
@@ -133,7 +133,19 @@ void BKE_nlastrips_sort_strips(ListBase *strips);
 
 /**
  * Add the given NLA-Strip to the given list of strips, assuming that it
- * isn't currently a member of another list
+ * isn't currently a member of another list, NULL, or conflicting with existing 
+ * strips position. 
+ */
+void BKE_nlastrips_add_strip_unsafe(ListBase *strips, struct NlaStrip *strip);
+
+/**
+ * @brief NULL checks incoming strip and verifies no overlap / invalid 
+ *  configuration against other strips in NLA Track.
+ *
+ * @param strips
+ * @param strip
+ * @return true
+ * @return false
  */
 bool BKE_nlastrips_add_strip(ListBase *strips, struct NlaStrip *strip);
 
diff --git a/source/blender/blenkernel/intern/nla.c b/source/blender/blenkernel/intern/nla.c
index 1ff7fc21b01..defa67ed664 100644
--- a/source/blender/blenkernel/intern/nla.c
+++ b/source/blender/blenkernel/intern/nla.c
@@ -764,20 +764,13 @@ void BKE_nlastrips_sort_strips(ListBase *strips)
   strips->last = tmp.last;
 }
 
-bool BKE_nlastrips_add_strip(ListBase *strips, NlaStrip *strip)
+void BKE_nlastrips_add_strip_unsafe(ListBase *strips, NlaStrip *strip)
 {
   NlaStrip *ns;
   bool not_added = true;
 
   /* sanity checks */
-  if (ELEM(NULL, strips, strip)) {
-    return false;
-  }
-
-  /* check if any space to add */
-  if (BKE_nlastrips_has_space(strips, strip->start, strip->end) == 0) {
-    return false;
-  }
+  BLI_assert(!ELEM(NULL, strips, strip));
 
   /* find the right place to add the strip to the nominated track */
   for (ns = strips->first; ns; ns = ns->next) {
@@ -792,8 +785,20 @@ bool BKE_nlastrips_add_strip(ListBase *strips, NlaStrip *strip)
     /* just add to the end of the list of the strips then... */
     BLI_addtail(strips, strip);
   }
+}
+
+/** NULL and Space check before adding in nlastrip */
+bool BKE_nlastrips_add_strip(ListBase *strips, NlaStrip *strip)
+{
+  if (ELEM(NULL, strips, strip)) {
+    return false;
+  }
+
+  if (!BKE_nlastrips_has_space(strips, strip->start, strip->end)) {
+    return false;
+  }
 
-  /* added... */
+  BKE_nlastrips_add_strip_unsafe(strips, strip);
   return true;
 }
 
diff --git a/source/blender/blenkernel/intern/nla_test.cc b/source/blender/blenkernel/intern/nla_test.cc
index 2f670ef69e5..b138baaaea0 100644
--- a/source/blender/blenkernel/intern/nla_test.cc
+++ b/source/blender/blenkernel/intern/nla_test.cc
@@ -39,4 +39,28 @@ TEST(nla_strip, BKE_nlastrip_recalculate_blend)
   EXPECT_FLOAT_EQ(strip.blendout, 0.1);
 }
 
+TEST(nla_strip, BKE_nlastrips_add_strip)
+{
+  ListBase strips{};
+  NlaStrip strip1{};
+  strip1.start = 0;
+  strip1.end = 10;
+  strips.first = &strip1;
+
+  NlaStrip strip2{};
+  strip2.start = 5;
+  strip2.end = 10;
+  
+  /*  can't add a null NLA strip to an NLA Track.   */
+  EXPECT_FALSE(BKE_nlastrips_add_strip(&strips, NULL));
+
+  /* can't add an NLA strip to an NLA Track that overlaps another NLA strip. */
+  EXPECT_FALSE(BKE_nlastrips_add_strip(&strips, &strip2));
+
+  strip2.start = 15;
+  strip2.end = 20;
+  /* can add an NLA strip to an NLA Track that doesn't overlaps another NLA strip. */
+  EXPECT_TRUE(BKE_nlastrips_add_strip(&strips, &strip2));
+}
+
 }  // namespace blender::bke::tests
diff --git a/source/blender/makesrna/intern/rna_nla.c b/source/blender/makesrna/intern/rna_nla.c
index b53b055cda8..ffd67b06037 100644
--- a/source/blender/makesrna/intern/rna_nla.c
+++ b/source/blender/makesrna/intern/rna_nla.c
@@ -539,7 +539,7 @@ static NlaStrip *rna_NlaStrip_new(ID *id,
   strip->end += (start - strip->start);
   strip->start = start;
 
-  if (BKE_nlastrips_add_strip(&track->strips, strip) == 0) {
+  if (BKE_nlastrips_add_strip(&track->strips, strip)) {
     BKE_report(
         reports,
         RPT_ERROR,