Prevent HTML minification from corrupting embedded WASM data - #27509
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Pass `--ignore-custom-fragments '[]'` to `html-minifier-terser`. By default, `html-minifier-terser` includes custom fragment regexes `/<%[\s\S]*?%>/` and `/<\?[\s\S]*?\?>/` intended for ignoring server-side preprocessor tags (like PHP `<?php ... ?>` or ASP `<% ... %>`). When matching these fragments, `html-minifier-terser` matches surrounding whitespace `\s*` and collapses it. When WASM binary data is embedded in JavaScript inside an HTML file (such as in `-sSINGLE_FILE=1` builds), arbitrary byte sequences in the WASM binary can happen to match `<?...?>` or `<%...%>`. In these cases, `html-minifier-terser` mistakes the binary data for preprocessor tags and collapses surrounding spaces (`0x20` bytes), corrupting the embedded WASM binary payload. Passing `--ignore-custom-fragments '[]'` disables this behavior. It is safe for Emscripten because generated HTML files are standard client-side documents, not server-side PHP/ASP template files containing preprocessor tags. Fixes: emscripten-core#27156
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Pass
--ignore-custom-fragments '[]'tohtml-minifier-terser.By default,
html-minifier-terserincludes custom fragment regexes/<%[\s\S]*?%>/and/<\?[\s\S]*?\?>/intended for ignoring server-sidepreprocessor tags (like PHP
<?php ... ?>or ASP<% ... %>). Whenmatching these fragments,
html-minifier-tersermatches surroundingwhitespace
\s*and collapses it.When WASM binary data is embedded in JavaScript inside an HTML file
(such as in
-sSINGLE_FILE=1builds), arbitrary byte sequences in theWASM binary can happen to match
<?...?>or<%...%>. In these cases,html-minifier-tersermistakes the binary data for preprocessor tagsand collapses surrounding spaces (
0x20bytes), corrupting the embeddedWASM binary payload.
Passing
--ignore-custom-fragments '[]'disables this behavior. It issafe for Emscripten because generated HTML files are standard
client-side documents, not server-side PHP/ASP template files containing
preprocessor tags.
Fixes: #27156