-syn region htmlItalic start="\\\@<!\*\S\@=" end="\S\zs\\\@<!\*" keepend oneline
-syn region htmlItalic start="\(^\|\s\)\@<=_\|\\\@<!_\([^_]\+\s\)\@=" end="\S\@<=[^\\]_\|[^\\]_\S\@=" keepend oneline
-syn region htmlBold start="\S\zs\*\*\|\*\*\S\@=" end="\S\zs\*\*\|\*\*\S\@=" keepend oneline
-syn region htmlBold start="\S\zs__\|__\S\@=" end="\S\zs__\|__\S\@=" keepend oneline
-syn region htmlBoldItalic start="\S\zs\*\*\*\|\*\*\*\S\@=" end="\S\zs\*\*\*\|\*\*\*\S\@=" keepend oneline
-syn region htmlBoldItalic start="\S\zs___\|___\S\@=" end="\S\zs___\|___\S\@=" keepend oneline
+"syn region htmlItalic start="\%(^\|\s\)\zs\*\ze[^\\\*\t ]" end="[^\\\*\t ]\zs\*\ze\_W" keepend
+"syn region htmlItalic start="\%(^\|\s\)\zs_\ze[^\\_\t ]" end="[^\\_\t ]\zs_\ze\_W" keepend
+"syn region htmlBold start="\*\*\ze\S" end="\S\zs\*\*" keepend
+"syn region htmlBold start="__\ze\S" end="\S\zs__" keepend
+"syn region htmlBoldItalic start="\*\*\*\ze\S" end="\S\zs\*\*\*" keepend
+"syn region htmlBoldItalic start="___\ze\S" end="\S\zs___" keepend
+
+" emphasis stops at newline (in case a closing token is not found before)
+"if get(g:, "vim_markdown_emphasis_stops_at_newline", 1)
+" let esanl_pre = '\(\n\|'
+" let esanl_suf = '\)'
+"else
+" let esanl_pre = ''
+" let esanl_suf = ''
+"endif
+"execute 'syn region htmlItalic start="\%(^\|\s\)\zs\*\ze[^\\\*\t ]" end="[^\\\*\t ]\zs' . esanl_pre . '\*' . esanl_suf . '\ze\_W" keepend'
+"execute 'syn region htmlItalic start="\%(^\|\s\)\zs_\ze[^\\_\t ]" end="[^\\_\t ]\zs' . esanl_pre . '_' . esanl_suf . '\ze\_W" keepend'
+"execute 'syn region htmlBold start="\*\*\ze\S" end="\S\zs' . esanl_pre . '\*\*' . esanl_suf . '" keepend'
+"execute 'syn region htmlBold start="__\ze\S" end="\S\zs__" keepend
+"execute 'syn region htmlBoldItalic start="\*\*\*\ze\S" end="\S\zs\*\*\*" keepend
+"execute 'syn region htmlBoldItalic start="___\ze\S" end="\S\zs___" keepend
+
+" single-line emphasis (emphasis only works with matching token in the same line)
+syn region htmlItalic start="\%(^\|\s\)\zs\*\ze[^\\\*\t ]\([^\n]*[^\\\*\t ]\)\?\*" end="[^\\\*\t ]\zs\*\ze\_W" keepend
+