Fix skip in pandocReferenceLabel to work with bracket in code in ref and add test

Author: itsjunetime

syntax/pandoc.vim

@@ -310,7 +310,7 @@ syn region pandocCodeBlockInsideIndent   start=/\(\(\d\|\a\|*\).*\n\)\@<!\(^\(\s
 " Links: {{{2
 
 " Base: {{{3
-syn region pandocReferenceLabel matchgroup=pandocOperator start=/!\{,1}\\\@<!\^\@<!\[/ end=/\\\@<!\]/ keepend display
+syn region pandocReferenceLabel matchgroup=pandocOperator start=/!\{,1}\\\@<!\^\@<!\[/ skip=/\(\\\@<!\]\]\@=\|`[^`]*`\)/ end=/\\\@<!\]/ keepend display
 if g:pandoc#syntax#conceal#urls == 1
     syn region pandocReferenceURL matchgroup=pandocOperator start=/\]\@1<=(/ end=/)/ keepend conceal
 else
@@ -502,7 +502,7 @@ syn match pandocUListItem /^>\=\s*[*+-]\s\+-\@!.*$/ nextgroup=pandocUListItem,pa
 call s:WithConceal('list', 'syn match pandocUListItemBullet /^>\=\s*\zs[*+-]/ contained containedin=pandocUListItem', 'conceal cchar='.s:cchars['li'])
 
 " Ordered lists
-syn match pandocListItem /^\s*(\?\(\d\+\|\l\|\#\|@\)[.)].*$/ nextgroup=pandocListItem,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocEscapedDollar,pandocDelimitedCodeBlock,pandocListItemContinuation contains=@Spell,pandocEmphasis,pandocStrong,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocEscapedDollar,pandocAutomaticLink,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID,pandocAmpersandEscape,pandocReferenceURL skipempty display
+syn match pandocListItem /^\s*(\?\(\d\+\|\l\|\#\|@\)[.)].*$/ nextgroup=pandocListItem,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocEscapedDollar,pandocDelimitedCodeBlock,pandocListItemContinuation contains=@Spell,pandocEmphasis,pandocStrong,pandocReferenceURL,pandocNoFormatted,pandocStrikeout,pandocSubscript,pandocSuperscript,pandocStrongEmphasis,pandocStrongEmphasis,pandocPCite,pandocICite,pandocCiteKey,pandocReferenceLabel,pandocLaTeXCommand,pandocLaTeXMathBlock,pandocLaTeXInlineMath,pandocEscapedDollar,pandocAutomaticLink,pandocFootnoteDef,pandocFootnoteBlock,pandocFootnoteID,pandocAmpersandEscape skipempty display
 
 " support for roman numerals up to 'c'
 if g:pandoc#syntax#roman_lists != 0

tests/refs.pdc

@@ -63,3 +63,7 @@ unit impulse (Dirac delta function) through a linear system.
 [`]`](http://foo.com) foo
 
 [Why isn't `ListT []`{.haskell} a monad](http://blog.sigfpe.com/2006/11/why-isnt-listt-monad.html)
+
+# code in ref with more code in same line
+
+1. [`link`](link) and more text `with code` and a [`link`](link)