Finally it seems like Xach got it right.

--Sven

ChangeLog

+Sun Dec 20 23:34:37 MET 1998 Sven Neumann <sven@gimp.org>
+
+	* app/rect_select.c: another patch from Xach. Eek, I should have
+	waited for him to finish his changes, but it seems to work 
+	correctly now.
+
 Sat Dec 19 15:46:27 CST 1998 Shawn T. Amundson <amundson@gtk.org>
 
 	* app/brush_edit.c:

app/rect_select.c

@@ -567,10 +567,20 @@ rect_select_motion (Tool           *tool,
     {
       if (rect_sel->fixed_size) 
 	{
-	  rect_sel->x = ox - (w/2);
-	  rect_sel->y = oy - (h/2);
-	  rect_sel->w = w;
-	  rect_sel->h = h;
+          if (mevent->state & GDK_SHIFT_MASK) 
+            {
+              rect_sel->x = ox - w;
+              rect_sel->y = oy - h;
+              rect_sel->w = w * 2;
+              rect_sel->h = h * 2;
+            }
+          else
+            {
+              rect_sel->x = ox - w / 2;
+              rect_sel->y = oy - h / 2;
+              rect_sel->w = w;
+              rect_sel->h = h;
+            }
 	} 
       else 
 	{

app/tools/gimprectselecttool.c

@@ -567,10 +567,20 @@ rect_select_motion (Tool           *tool,
     {
       if (rect_sel->fixed_size) 
 	{
-	  rect_sel->x = ox - (w/2);
-	  rect_sel->y = oy - (h/2);
-	  rect_sel->w = w;
-	  rect_sel->h = h;
+          if (mevent->state & GDK_SHIFT_MASK) 
+            {
+              rect_sel->x = ox - w;
+              rect_sel->y = oy - h;
+              rect_sel->w = w * 2;
+              rect_sel->h = h * 2;
+            }
+          else
+            {
+              rect_sel->x = ox - w / 2;
+              rect_sel->y = oy - h / 2;
+              rect_sel->w = w;
+              rect_sel->h = h;
+            }
 	} 
       else 
 	{

app/tools/rect_select.c

@@ -567,10 +567,20 @@ rect_select_motion (Tool           *tool,
     {
       if (rect_sel->fixed_size) 
 	{
-	  rect_sel->x = ox - (w/2);
-	  rect_sel->y = oy - (h/2);
-	  rect_sel->w = w;
-	  rect_sel->h = h;
+          if (mevent->state & GDK_SHIFT_MASK) 
+            {
+              rect_sel->x = ox - w;
+              rect_sel->y = oy - h;
+              rect_sel->w = w * 2;
+              rect_sel->h = h * 2;
+            }
+          else
+            {
+              rect_sel->x = ox - w / 2;
+              rect_sel->y = oy - h / 2;
+              rect_sel->w = w;
+              rect_sel->h = h;
+            }
 	} 
       else 
 	{