Fix T80135: Duplicate doesn't preserve active spline

Checks to preserve the active spline on duplication
required an active vertex too.

Now having no active vertex doesn't prevent duplicate
from keeping the spline active.

Reviewed by: @mano-wii

Ref D8729

1 files changed, 65 insertions, 40 deletions

diff --git a/source/blender/editors/curve/editcurve.c b/source/blender/editors/curve/editcurve.c
index 91a8ea0fa3a..e5d83689143 100644
--- a/source/blender/editors/curve/editcurve.c
+++ b/source/blender/editors/curve/editcurve.c
@@ -2169,12 +2169,22 @@ bool ed_editnurb_extrude_flag(EditNurb *editnurb, const short flag)
   return ok;
 }
 
+static void calc_duplicate_actnurb(const ListBase *editnurb, const ListBase *newnurb, Curve *cu)
+{
+  cu->actnu = BLI_listbase_count(editnurb) + BLI_listbase_count(newnurb);
+}
+
 static bool calc_duplicate_actvert(
     const ListBase *editnurb, const ListBase *newnurb, Curve *cu, int start, int end, int vert)
 {
+  if (cu->actvert == -1) {
+    calc_duplicate_actnurb(editnurb, newnurb, cu);
+    return true;
+  }
+
   if ((start <= cu->actvert) && (end > cu->actvert)) {
+    calc_duplicate_actnurb(editnurb, newnurb, cu);
     cu->actvert = vert;
-    cu->actnu = BLI_listbase_count(editnurb) + BLI_listbase_count(newnurb);
     return true;
   }
   return false;
@@ -2424,26 +2434,31 @@ static void adduplicateflagNurb(
                 }
 
                 if (cu->actnu == i) {
-                  for (b = 0, diffa = 0; b < newv; b++, diffa += nu->pntsu - newu) {
-                    starta = b * nu->pntsu + a;
-                    if (calc_duplicate_actvert(editnurb,
-                                               newnurb,
-                                               cu,
-                                               cu->actvert,
-                                               starta,
-                                               cu->actvert % nu->pntsu + newu +
-                                                   b * newnu->pntsu)) {
-                      /* actvert in cyclicu selection */
-                      break;
-                    }
-                    if (calc_duplicate_actvert(editnurb,
-                                               newnurb,
-                                               cu,
-                                               starta,
-                                               starta + newu,
-                                               cu->actvert - starta + b * newnu->pntsu)) {
-                      /* actvert in 'current' iteration selection */
-                      break;
+                  if (cu->actvert == -1) {
+                    calc_duplicate_actnurb(editnurb, newnurb, cu);
+                  }
+                  else {
+                    for (b = 0, diffa = 0; b < newv; b++, diffa += nu->pntsu - newu) {
+                      starta = b * nu->pntsu + a;
+                      if (calc_duplicate_actvert(editnurb,
+                                                 newnurb,
+                                                 cu,
+                                                 cu->actvert,
+                                                 starta,
+                                                 cu->actvert % nu->pntsu + newu +
+                                                     b * newnu->pntsu)) {
+                        /* actvert in cyclicu selection */
+                        break;
+                      }
+                      if (calc_duplicate_actvert(editnurb,
+                                                 newnurb,
+                                                 cu,
+                                                 starta,
+                                                 starta + newu,
+                                                 cu->actvert - starta + b * newnu->pntsu)) {
+                        /* actvert in 'current' iteration selection */
+                        break;
+                      }
                     }
                   }
                 }
@@ -2471,16 +2486,21 @@ static void adduplicateflagNurb(
 
               /* general case if not handled by cyclicu or cyclicv */
               if (cu->actnu == i) {
-                for (b = 0, diffa = 0; b < newv; b++, diffa += nu->pntsu - newu) {
-                  starta = b * nu->pntsu + a;
-                  if (calc_duplicate_actvert(editnurb,
-                                             newnurb,
-                                             cu,
-                                             starta,
-                                             starta + newu,
-                                             cu->actvert - (a / nu->pntsu * nu->pntsu + diffa +
-                                                            (starta % nu->pntsu)))) {
-                    break;
+                if (cu->actvert == -1) {
+                  calc_duplicate_actnurb(editnurb, newnurb, cu);
+                }
+                else {
+                  for (b = 0, diffa = 0; b < newv; b++, diffa += nu->pntsu - newu) {
+                    starta = b * nu->pntsu + a;
+                    if (calc_duplicate_actvert(editnurb,
+                                               newnurb,
+                                               cu,
+                                               starta,
+                                               starta + newu,
+                                               cu->actvert - (a / nu->pntsu * nu->pntsu + diffa +
+                                                              (starta % nu->pntsu)))) {
+                      break;
+                    }
                   }
                 }
               }
@@ -2507,15 +2527,20 @@ static void adduplicateflagNurb(
 
             /* check for actvert in the unused cyclicuv selection */
             if (cu->actnu == i) {
-              for (b = 0, diffa = 0; b < newv; b++, diffa += nu->pntsu - newu) {
-                starta = b * nu->pntsu;
-                if (calc_duplicate_actvert(editnurb,
-                                           newnurb,
-                                           cu,
-                                           starta,
-                                           starta + newu,
-                                           cu->actvert - (diffa + (starta % nu->pntsu)))) {
-                  break;
+              if (cu->actvert == -1) {
+                calc_duplicate_actnurb(editnurb, newnurb, cu);
+              }
+              else {
+                for (b = 0, diffa = 0; b < newv; b++, diffa += nu->pntsu - newu) {
+                  starta = b * nu->pntsu;
+                  if (calc_duplicate_actvert(editnurb,
+                                             newnurb,
+                                             cu,
+                                             starta,
+                                             starta + newu,
+                                             cu->actvert - (diffa + (starta % nu->pntsu)))) {
+                    break;
+                  }
                 }
               }
             }