Trim even spaces only in code

Fix #1403

Author: nobu

lib/rdoc/markdown.kpeg

@@ -501,6 +501,8 @@
   # Wraps `text` in code markup for rdoc inline formatting
 
   def code text
+    # trim even spaces
+    text = $2 while /\A( +|\t+)(.*)\1\z/ =~ text
     # escape unescaped backslash at the end
     backslash_at_end = "\\" if /(?<!\\)(?:\\\\)*\\\z/.match?(text)
     "<code>#{text}#{backslash_at_end}</code>"
@@ -1113,30 +1115,30 @@ Ticks3 = "```" !"`"
 Ticks4 = "````" !"`"
 Ticks5 = "`````" !"`"
 
-Code = ( Ticks1 @Sp < (
+Code = ( Ticks1 < (
            ( !"`" Nonspacechar )+ | !Ticks1 /`+/ |
-           !( @Sp Ticks1 ) ( @Spacechar | @Newline !@BlankLine )
-         )+ > @Sp Ticks1 |
-         Ticks2 @Sp < (
+           !Ticks1 ( @Spacechar | @Newline !@BlankLine )
+         )+ > Ticks1 |
+         Ticks2 < (
            ( !"`" Nonspacechar )+ |
            !Ticks2 /`+/ |
-           !( @Sp Ticks2 ) ( @Spacechar | @Newline !@BlankLine )
-         )+ > @Sp Ticks2 |
-         Ticks3 @Sp < (
+           !Ticks2 ( @Spacechar | @Newline !@BlankLine )
+         )+ > Ticks2 |
+         Ticks3 < (
            ( !"`" Nonspacechar )+ |
            !Ticks3 /`+/ |
-           !( @Sp Ticks3 ) ( @Spacechar | @Newline !@BlankLine )
-         )+ > @Sp Ticks3 |
-         Ticks4 @Sp < (
+           !Ticks3 ( @Spacechar | @Newline !@BlankLine )
+         )+ > Ticks3 |
+         Ticks4 < (
            ( !"`" Nonspacechar )+ |
            !Ticks4 /`+/ |
-           !( @Sp Ticks4 ) ( @Spacechar | @Newline !@BlankLine )
-         )+ > @Sp Ticks4 |
-         Ticks5 @Sp < (
+           !Ticks4 ( @Spacechar | @Newline !@BlankLine )
+         )+ > Ticks4 |
+         Ticks5 < (
            ( !"`" Nonspacechar )+ |
            !Ticks5 /`+/ |
-           !( @Sp Ticks5 ) ( @Spacechar | @Newline !@BlankLine )
-         )+ > @Sp Ticks5
+           !Ticks5 ( @Spacechar | @Newline !@BlankLine )
+         )+ > Ticks5
        )
        { code text }
 

test/rdoc/rdoc_markdown_test.rb

@@ -139,6 +139,14 @@ def test_parse_code
     expected = doc(para("Code: <code>text</code>"))
     assert_equal expected, doc
 
+    doc = parse "Code: ` text`"
+    expected = doc(para("Code: <code> text</code>"))
+    assert_equal expected, doc
+
+    doc = parse "Code: `text `"
+    expected = doc(para("Code: <code>text </code>"))
+    assert_equal expected, doc
+
     doc = parse "Code: ` text `"
     expected = doc(para("Code: <code>text</code>"))
     assert_equal expected, doc
@@ -147,6 +155,14 @@ def test_parse_code
     expected = doc(para("Code: <code>text`s</code>"))
     assert_equal expected, doc
 
+    doc = parse "Code: `` text`s``"
+    expected = doc(para("Code: <code> text`s</code>"))
+    assert_equal expected, doc
+
+    doc = parse "Code: ``text`s ``"
+    expected = doc(para("Code: <code>text`s </code>"))
+    assert_equal expected, doc
+
     doc = parse "Code: `` text`s ``"
     expected = doc(para("Code: <code>text`s</code>"))
     assert_equal expected, doc
@@ -155,6 +171,14 @@ def test_parse_code
     expected = doc(para("Code: <code>text`s</code>"))
     assert_equal expected, doc
 
+    doc = parse "Code: ``` text`s```"
+    expected = doc(para("Code: <code> text`s</code>"))
+    assert_equal expected, doc
+
+    doc = parse "Code: ```text`s ```"
+    expected = doc(para("Code: <code>text`s </code>"))
+    assert_equal expected, doc
+
     doc = parse "Code: ``` text`s ```"
     expected = doc(para("Code: <code>text`s</code>"))
     assert_equal expected, doc
@@ -223,7 +247,7 @@ def test_parse_code_github_format
     doc = <<-MD
 Example:
 
-``` ruby
+```ruby
 code goes here
 ```
     MD
@@ -1201,14 +1225,14 @@ def test_gfm_table_with_backslashes_in_code_spans
 
     body = [
       ['Plain', '<code>$\\\\</code>', 'Should show backslash'],
-      ['Escaped', '<code>$\\\\</code>', 'Should show backslash'],
+      ['Escaped', '<code>$\\\\ </code>', 'Should show backslash'],
       ['Multiple', '<code>\\\\n\\\\t</code>', 'Should show backslashes'],
     ]
 
     expected_table = @RM::Table.new(head, align, body)
 
     expected = doc(
-      para('Plain text: <code>$\\\\</code> and <code>$\\\\</code> should work.'),
+      para('Plain text: <code>$\\\\</code> and <code>$\\\\ </code> should work.'),
       expected_table
     )