Eliminate drift of origin if mirroring occurs during scaling/stretching

diff --git a/src/seltrans.cpp b/src/seltrans.cpp
index 52afc0e1484a14e9fed0c49420d2ba459ffdb3da..21b8a046131aa7115ee12c83fb5a1545d039c115 100644 (file)
--- a/src/seltrans.cpp
+++ b/src/seltrans.cpp
@@ -1355,8 +1355,13 @@ void Inkscape::SelTrans::stretch(SPSelTransHandle const &handle, NR::Point &pt,
         return;
     }
 
-    NR::Point new_bbox_min = _approximate_bbox->min() * (NR::translate(-scale_origin) * NR::Matrix(s) * NR::translate(scale_origin));
-    NR::Point new_bbox_max = _approximate_bbox->max() * (NR::translate(-scale_origin) * NR::Matrix(s) * NR::translate(scale_origin));
+    //Get two corners of the new bbox
+    NR::Point p1 = _approximate_bbox->min() * (NR::translate(-scale_origin) * NR::Matrix(s) * NR::translate(scale_origin));
+    NR::Point p2 = _approximate_bbox->max() * (NR::translate(-scale_origin) * NR::Matrix(s) * NR::translate(scale_origin));
+
+    //Find the ones at the lower-left and upper-right, as required by get_scale_transform_with_stroke
+    NR::Point new_bbox_min = NR::Point(std::min(p1[NR::X], p2[NR::X]), std::min(p1[NR::Y], p2[NR::Y]));
+    NR::Point new_bbox_max = NR::Point(std::max(p1[NR::X], p2[NR::X]), std::max(p1[NR::Y], p2[NR::Y]));
 
     int transform_stroke = false;
     gdouble strokewidth = 0;
@@ -1387,9 +1392,15 @@ void Inkscape::SelTrans::scale(NR::Point &pt, guint state)
         if (fabs(s[i]) < 1e-9)
             s[i] = 1e-9;
     }
-    NR::Point new_bbox_min = _approximate_bbox->min() * (NR::translate(-_origin) * NR::Matrix(s) * NR::translate(_origin));
-    NR::Point new_bbox_max = _approximate_bbox->max() * (NR::translate(-_origin) * NR::Matrix(s) * NR::translate(_origin));
+    
+    //Get two corners of the new bbox
+    NR::Point p1 = _approximate_bbox->min() * (NR::translate(-_origin) * NR::Matrix(s) * NR::translate(_origin));
+    NR::Point p2 = _approximate_bbox->max() * (NR::translate(-_origin) * NR::Matrix(s) * NR::translate(_origin));
 
+    //Find the ones at the lower-left and upper-right, as required by get_scale_transform_with_stroke
+    NR::Point new_bbox_min = NR::Point(std::min(p1[NR::X], p2[NR::X]), std::min(p1[NR::Y], p2[NR::Y]));
+    NR::Point new_bbox_max = NR::Point(std::max(p1[NR::X], p2[NR::X]), std::max(p1[NR::Y], p2[NR::Y]));
+    
     int transform_stroke = false;
     gdouble strokewidth = 0;