From f0c61427f3324b610404f1146b53639380e43dbd Mon Sep 17 00:00:00 2001
From: Brian Goff <cpuguy83@gmail.com>
Date: Mon, 5 Feb 2024 01:00:01 +0000
Subject: [PATCH] Fix escape characters for content with newline

Given an input like so:

```markdown
'foo'
'bar'
```

We should be escaping both opening `'`.
Before this change only the first was escaped because we only look at
the first character of a `[]byte` and did not account for newlines.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
---
 md2man/roff.go      | 23 +++++++++++++++++++++++
 md2man/roff_test.go | 32 ++++++++++++++++++--------------
 2 files changed, 41 insertions(+), 14 deletions(-)

diff --git a/md2man/roff.go b/md2man/roff.go
index 4b19188..66cc9b0 100644
--- a/md2man/roff.go
+++ b/md2man/roff.go
@@ -1,6 +1,7 @@
 package md2man
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
 	"io"
@@ -322,6 +323,28 @@ func out(w io.Writer, output string) {
 }
 
 func escapeSpecialChars(w io.Writer, text []byte) {
+	scanner := bufio.NewScanner(bytes.NewReader(text))
+
+	// count the number of lines in the text
+	// we need to know this to avoid adding a newline after the last line
+	n := bytes.Count(text, []byte{'\n'})
+	idx := 0
+
+	for scanner.Scan() {
+		dt := scanner.Bytes()
+		if idx < n {
+			idx++
+			dt = append(dt, '\n')
+		}
+		escapeSpecialCharsLine(w, dt)
+	}
+
+	if err := scanner.Err(); err != nil {
+		panic(err)
+	}
+}
+
+func escapeSpecialCharsLine(w io.Writer, text []byte) {
 	for i := 0; i < len(text); i++ {
 		// escape initial apostrophe or period
 		if len(text) >= 1 && (text[0] == '\'' || text[0] == '.') {
diff --git a/md2man/roff_test.go b/md2man/roff_test.go
index af03326..dee4862 100644
--- a/md2man/roff_test.go
+++ b/md2man/roff_test.go
@@ -360,6 +360,8 @@ func TestEscapeCharacters(t *testing.T) {
 	tests := []string{
 		"Test-one_two&three\\four~five",
 		".nh\n\n.PP\nTest-one_two&three\\\\four~five\n",
+		"'foo'\n'bar'",
+		".nh\n\n.PP\n\\&'foo'\n\\&'bar'\n",
 	}
 	doTestsInline(t, tests)
 }
@@ -438,23 +440,25 @@ func doTestsParam(t *testing.T, tests []string, params TestParams) {
 	execRecoverableTestSuite(t, tests, params, func(candidate *string) {
 		for i := 0; i+1 < len(tests); i += 2 {
 			input := tests[i]
-			*candidate = input
-			expected := tests[i+1]
-			actual := runMarkdown(*candidate, params)
-			if actual != expected {
-				t.Errorf("\nInput   [%#v]\nExpected[%#v]\nActual  [%#v]",
-					*candidate, expected, actual)
-			}
+			t.Run(input, func(t *testing.T) {
+				*candidate = input
+				expected := tests[i+1]
+				actual := runMarkdown(*candidate, params)
+				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, params)
+				// 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, params)
+						}
 					}
 				}
-			}
+			})
 		}
 	})
 }