diff --git a/block.go b/block.go
index 3f4af78..3fa1e92 100644
--- a/block.go
+++ b/block.go
@@ -515,7 +515,7 @@ func (p *parser) htmlFindEnd(tag string, data []byte) int {
 	return i + skip
 }
 
-func (p *parser) isEmpty(data []byte) int {
+func (*parser) isEmpty(data []byte) int {
 	// it is okay to call isEmpty on an empty buffer
 	if len(data) == 0 {
 		return 0
@@ -530,7 +530,7 @@ func (p *parser) isEmpty(data []byte) int {
 	return i + 1
 }
 
-func (p *parser) isHRule(data []byte) bool {
+func (*parser) isHRule(data []byte) bool {
 	i := 0
 
 	// skip up to three spaces
diff --git a/inline_test.go b/inline_test.go
index 9fb937b..bcaba09 100644
--- a/inline_test.go
+++ b/inline_test.go
@@ -59,13 +59,11 @@ func doTestsInlineParam(t *testing.T, tests []string, opts Options, htmlFlags in
 	params HtmlRendererParameters) {
 	// catch and report panics
 	var candidate string
-	/*
-		defer func() {
-			if err := recover(); err != nil {
-				t.Errorf("\npanic while processing [%#v] (%v)\n", candidate, err)
-			}
-		}()
-	*/
+	defer func() {
+		if err := recover(); err != nil {
+			t.Errorf("\npanic while processing [%#v]: %s\n", candidate, err)
+		}
+	}()
 
 	for i := 0; i+1 < len(tests); i += 2 {
 		input := tests[i]
@@ -722,10 +720,6 @@ func TestReferenceLink(t *testing.T) {
 
 		"[link][ref]\n   [ref]: /url/",
 		"<p><a href=\"/url/\">link</a></p>\n",
-
-		// Issue 172 in blackfriday
-		"[]:<",
-		"<p>[]:&lt;</p>\n",
 	}
 	doLinkTestsInline(t, tests)
 }
diff --git a/markdown_test.go b/markdown_test.go
new file mode 100644
index 0000000..d897644
--- /dev/null
+++ b/markdown_test.go
@@ -0,0 +1,75 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+// Unit tests for full document parsing and rendering
+//
+
+package blackfriday
+
+import (
+	"testing"
+)
+
+func runMarkdown(input string) string {
+	return string(MarkdownCommon([]byte(input)))
+}
+
+func doTests(t *testing.T, tests []string) {
+	// catch and report panics
+	var candidate string
+	defer func() {
+		if err := recover(); err != nil {
+			t.Errorf("\npanic while processing [%#v]: %s\n", candidate, err)
+		}
+	}()
+
+	for i := 0; i+1 < len(tests); i += 2 {
+		input := tests[i]
+		candidate = input
+		expected := tests[i+1]
+		actual := runMarkdown(candidate)
+		if actual != expected {
+			t.Errorf("\nInput   [%#v]\nExpected[%#v]\nActual  [%#v]",
+				candidate, expected, actual)
+		}
+
+		// now test every substring to stress test bounds checking
+		if !testing.Short() {
+			for start := 0; start < len(input); start++ {
+				for end := start + 1; end <= len(input); end++ {
+					candidate = input[start:end]
+					_ = runMarkdown(candidate)
+				}
+			}
+		}
+	}
+}
+
+func TestDocument(t *testing.T) {
+	var tests = []string{
+		// Empty document.
+		"",
+		"",
+
+		" ",
+		"",
+
+		// This shouldn't panic.
+		// https://github.com/russross/blackfriday/issues/172
+		"[]:<",
+		"<p>[]:&lt;</p>\n",
+
+		// This shouldn't panic.
+		// https://github.com/russross/blackfriday/issues/173
+		"   [",
+		"<p>[</p>\n",
+	}
+	doTests(t, tests)
+}
diff --git a/ref_test.go b/ref_test.go
index 770439c..733a63a 100644
--- a/ref_test.go
+++ b/ref_test.go
@@ -29,7 +29,7 @@ func doTestsReference(t *testing.T, files []string, flag int) {
 	var candidate string
 	defer func() {
 		if err := recover(); err != nil {
-			t.Errorf("\npanic while processing [%#v]\n", candidate)
+			t.Errorf("\npanic while processing [%#v]: %s\n", candidate, err)
 		}
 	}()