Merge pull request #829 from snnz/fix-emphasis-span

Fix incorrect emphasis span calculation.

Author: xoofx

src/Markdig.Tests/TestSourcePosition.cs

@@ -160,6 +160,17 @@ public void TestEmphasis3()
 ");
     }
 
+    [Test]
+    public void TestEmphasis4()
+    {
+        Check("**foo*", @"
+paragraph    ( 0, 0)  0-5
+literal      ( 0, 0)  0-0
+emphasis     ( 0, 1)  1-5
+literal      ( 0, 2)  2-4
+");
+    }
+
     [Test]
     public void TestEmphasisFalse()
     {

src/Markdig/Parsers/Inlines/EmphasisInlineParser.cs

@@ -302,14 +302,13 @@ private void ProcessEmphasis(InlineProcessor processor, List<EmphasisDelimiterIn
                         var openDelimitercount = openDelimiter.DelimiterCount;
                         var closeDelimitercount = closeDelimiter.DelimiterCount;
 
-                        emphasis!.Span.Start = openDelimiter.Span.Start;
+                        emphasis!.Span.Start = openDelimiter.Span.Start + openDelimitercount - delimiterDelta;
                         emphasis.Line = openDelimiter.Line;
-                        emphasis.Column = openDelimiter.Column;
+                        emphasis.Column = openDelimiter.Column + openDelimitercount - delimiterDelta;
                         emphasis.Span.End = closeDelimiter.Span.End - closeDelimitercount + delimiterDelta;
 
-                        openDelimiter.Content.Start += delimiterDelta;
-                        openDelimiter.Span.Start += delimiterDelta;
-                        openDelimiter.Column += delimiterDelta;
+                        openDelimiter.Span.End -= delimiterDelta;
+                        openDelimiter.Content.End -= delimiterDelta;
                         closeDelimiter.Content.Start += delimiterDelta;
                         closeDelimiter.Span.Start += delimiterDelta;
                         closeDelimiter.Column += delimiterDelta;