bugfix [#24291] Error parenting a child with any negative scaling coordinate

the bug was in object_apply_mat4(), caused by applying a non-normalized matrix to the rotation.
Blender 2.4x also had this problem, surprising nobody noticed!.

2 files changed, 22 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 77ebcb24975..294546bb222 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -102,7 +102,9 @@ void transpose_m3(float R[3][3]);
 void transpose_m4(float R[4][4]);
 
 void normalize_m3(float R[3][3]);
+void normalize_m3_m3(float R[3][3], float A[3][3]);
 void normalize_m4(float R[4][4]);
+void normalize_m4_m4(float R[4][4], float A[4][4]);
 
 void orthogonalize_m3(float R[3][3], int axis);
 void orthogonalize_m4(float R[4][4], int axis);
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index 3b5ffa2d442..197d3676367 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -750,6 +750,14 @@ void normalize_m3(float mat[][3])
 	normalize_v3(mat[2]);
 }
 
+void normalize_m3_m3(float rmat[][3], float mat[][3])
+{	
+	normalize_v3_v3(rmat[0], mat[0]);
+	normalize_v3_v3(rmat[1], mat[1]);
+	normalize_v3_v3(rmat[2], mat[2]);
+}
+
+
 void normalize_m4(float mat[][4])
 {
 	float len;
@@ -762,6 +770,18 @@ void normalize_m4(float mat[][4])
 	if(len!=0.0) mat[2][3]/= len;
 }
 
+void normalize_m4_m4(float rmat[][4], float mat[][4])
+{
+	float len;
+	
+	len= normalize_v3_v3(rmat[0], mat[0]);
+	if(len!=0.0) rmat[0][3]= mat[0][3] / len;
+	len= normalize_v3_v3(rmat[1], mat[1]);
+	if(len!=0.0) rmat[1][3]= mat[1][3] / len;
+	len= normalize_v3_v3(rmat[2], mat[2]);
+	if(len!=0.0) rmat[2][3]= mat[2][3] / len;;
+}
+
 void adjoint_m3_m3(float m1[][3], float m[][3])
 {
 	m1[0][0]=m[1][1]*m[2][2]-m[1][2]*m[2][1];