Fix empty lines of consecutive line break tags

Author: eXpl0it3r

Source/HtmlRenderer/Core/Parse/DomParser.cs

@@ -638,9 +638,9 @@ private static void CorrectImgBoxes(CssBox box)
         }
 
         /// <summary>
-        /// Correct the DOM tree recursively by turning "br" html boxes that should force a line break
-        /// into a "\n" text word on the box itself, reusing the same forced-newline mechanism used for
-        /// "white-space: pre/pre-line" content.
+        /// Correct the DOM tree recursively by replacing  "br" html boxes with anonymous blocks that respect br spec.<br/>
+        /// If the "br" tag is after inline box then the anon block will have zero height only acting as newline,
+        /// but if it is after block box then it will have min-height of the font size so it will create empty line.
         /// </summary>
         /// <param name="box">the current box to correct its sub-tree</param>
         private static void CorrectLineBreaksBlocks(CssBox box)
@@ -650,16 +650,27 @@ private static void CorrectLineBreaksBlocks(CssBox box)
                 CorrectLineBreaksBlocks(childBox);
             }
 
-            if (!box.IsBrElement) return;
-
-            var previousSibling = DomUtils.GetPreviousSibling(box);
-            if (previousSibling == null || previousSibling.IsBlock)
+            var followingBlock = box.IsBlock;
+            foreach (var childBox in box.Boxes)
             {
-                var nextSibling = DomUtils.GetFollowingSiblings(box, b => b.IsInline && !b.IsBrElement, true).FirstOrDefault();
-                if (nextSibling == null)
+                if (childBox.IsBrElement)
+                {
+                    childBox.Display = CssConstants.Block;
+                    if (followingBlock)
+                    {
+                        childBox.Height = ".95em"; // TODO:a check the height to min-height when it is supported
+                    }
+
+                    // A BR itself is block-level after correction, so a following BR is treated as an empty-line break.
+                    followingBlock = true;
+                }
+                else if (childBox.Words.Count > 0)
+                {
+                    followingBlock = false;
+                }
+                else if (childBox.IsBlock)
                 {
-                    box.Text = "\n";
-                    box.ParseToWords();
+                    followingBlock = true;
                 }
             }
         }