Index: misc/tabledrag.js
===================================================================
RCS file: /cvs/drupal/drupal/misc/tabledrag.js,v
retrieving revision 1.9
diff -u -r1.9 tabledrag.js
--- misc/tabledrag.js	6 Dec 2007 09:53:53 -0000	1.9
+++ misc/tabledrag.js	12 Dec 2007 22:31:02 -0000
@@ -269,6 +269,7 @@
           keyChange = true;
           if (self.rowObject.isValidSwap(previousRow, 0)) {
             self.rowObject.swap('before', previousRow);
+            self.rowObject.indent(0);
             window.scrollBy(0, -parseInt(item.offsetHeight));
           }
           else if (self.table.tBodies[0].rows[0] != previousRow || $(previousRow).is('.draggable')) {
@@ -294,15 +295,18 @@
           self.safeBlur = false; // Do not allow the onBlur cleanup.
           self.rowObject.direction = 'down';
           keyChange = true;
+
           if (self.rowObject.isValidSwap(nextRow, 0)) {
             self.rowObject.swap('after', nextRow);
+            self.rowObject.indent(0);
+            window.scrollBy(0, parseInt(item.offsetHeight));
           }
           else {
             self.rowObject.swap('after', nextRow);
             self.rowObject.indent(-1);
+            window.scrollBy(0, parseInt(item.offsetHeight));
           }
           handle.get(0).focus(); // Regain focus after the DOM manipulation.
-          window.scrollBy(0, parseInt(item.offsetHeight));
         }
         break;
     }
@@ -375,7 +379,7 @@
     }
 
     // Similar to row swapping, handle indentations.
-    if (self.indentEnabled && x != self.oldX) {
+    if (self.indentEnabled) {
       self.oldX = x;
       var xDiff = self.currentMouseCoords.x - self.dragObject.indentMousePos.x;
       // Set the number of indentations the mouse has been moved left or right.
@@ -383,17 +387,14 @@
       // Limit the indentation to no less than the left edge of the table and no
       // more than the total amount of indentation in the table.
       indentDiff = indentDiff > 0 ? Math.min(indentDiff, self.indentCount - self.rowObject.indents + 1) : Math.max(indentDiff, -self.rowObject.indents);
-      if (indentDiff != 0) {
-        // Indent the row with our estimated diff, which may be further
-        // restricted according to the rows around this row.
-        var indentChange = self.rowObject.indent(indentDiff);
-
-        // Update table and mouse indentations.
-        self.dragObject.indentMousePos.x += self.indentAmount * indentChange;
-        self.indentCount = Math.max(self.indentCount, self.rowObject.indents);
-      }
+      // Indent the row with our estimated diff, which may be further
+      // restricted according to the rows around this row.
+      var indentChange = self.rowObject.indent(indentDiff);
+
+      // Update table and mouse indentations.
+      self.dragObject.indentMousePos.x += self.indentAmount * indentChange;
+      self.indentCount = Math.max(self.indentCount, self.rowObject.indents);
     }
-
     return false;
   }
 };
@@ -547,7 +548,7 @@
         return null;
       }
 
-      // We've may have found the row the mouse just passed over, but it doesn't
+      // We may have found the row the mouse just passed over, but it doesn't
       // take into account hidden rows. Skip backwards until we find a draggable
       // row.
       while ($(row).is(':hidden') && $(row).prev('tr').is(':hidden')) {
@@ -861,13 +862,17 @@
     var rowIndents = $('.indentation', row).size();
     var prevIndents = $('.indentation', $(row).prev('tr')).size();
     var nextIndents = $('.indentation', $(row).next('tr')).size();
+    var indentAllowed = !$(this.element).is('.no-parent');
 
     if (
       (this.direction == 'down') && (
         // Prevent being able to drag a row downward with 2 indentations from a parent.
         this.indents > rowIndents + 1 ||
         // Prevent orphaning children when dragging into a parent.
-        this.indents < nextIndents - indentDiff
+        this.indents < nextIndents - indentDiff ||
+        // Prevent orphaning children when dragging into a parent if the
+        // current row can't be nested.
+        (!indentAllowed && indentDiff && nextIndents)
       ) ||
       (this.direction == 'up') && (
         // Prevent being able to drag a row upward with 2 indentations from a parent.
@@ -914,24 +919,34 @@
  *   positive.
  */
 Drupal.tableDrag.prototype.row.prototype.indent = function(indentDiff) {
-  if (indentDiff > 0) {
-    var prevRow = $(this.group).filter(':first').prev('tr').get(0);
-    if (prevRow) {
-      var prevIndent = $('.indentation', $(this.group).filter(':first').prev('tr')).size();
-      indentDiff = Math.min(prevIndent - this.indents + 1, indentDiff);
+  if ($(this.element).is('.no-parent')) {
+    indentDiff = -this.indents;
+  }
+  else {
+    // Find the deepest suitable parent.
+    var parentRow = $(this.element).prev('tr').get(0);
+    while (parentRow && $(parentRow).is('.no-child') && $('.indentation', parentRow).size()) {
+      parentRow = $(parentRow).prev('tr').get(0);
+    }
+    if (parentRow && !$(parentRow).is('.no-child')) {
+      // Set as a child of the parent we found.
+      var parentIndent = $('.indentation', parentRow).size();
+      indentDiff = Math.min(parentIndent - this.indents + 1, indentDiff);
     }
     else {
-      indentDiff = 0; // First row may not contain indents.
+      // No suitable parent was found : no indentation.
+      indentDiff = -this.indents;
+    }
+
+    if (indentDiff < 0) {
+      var nextIndent = $('.indentation', $(this.group).filter(':last').next('tr')).size();
+      indentDiff = Math.max(nextIndent - this.indents, indentDiff);
     }
-  }
-  else {
-    var nextIndent = $('.indentation', $(this.group).filter(':last').next('tr')).size();
-    indentDiff = Math.max(nextIndent - this.indents, indentDiff);
-  }
 
-  // Never allow indentation greater the set limit.
-  if (this.maxDepth && indentDiff + this.groupDepth > this.maxDepth) {
-    indentDiff = 0;
+    // Never allow indentation greater than the set limit.
+    if (this.maxDepth && indentDiff + this.groupDepth > this.maxDepth) {
+      indentDiff = 0;
+    }
   }
 
   for (var n = 1; n <= Math.abs(indentDiff); n++) {