module: don't read a phantom name on the last mapping segment#63801
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dusanstanojeviccs wants to merge 1 commit into
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module: don't read a phantom name on the last mapping segment#63801dusanstanojeviccs wants to merge 1 commit into
dusanstanojeviccs wants to merge 1 commit into
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SourceMap#parseMap reads the optional name VLQ guarded only by !isSeparator(peek()). At the end of the mappings string peek() returns '', which is not a separator, so the parser decodes a phantom VLQ (0), keeps the previous nameIndex, and assigns names[nameIndex] to a segment that has no name field. SourceMap.findEntry() then returns a stale name, which surfaces as the wrong function name on the bottom global frame of --enable-source-maps stack traces. Guard the name read with hasNext() so the phantom field is not read at end of string. A trailing segment that genuinely carries a name still has characters left to read, so it is unaffected. Refs: nodejs#63795 Signed-off-by: Dusan Stanojevic <dusan.stanojevic.cs@gmail.com>
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Fixes a stale-name bug in
SourceMap's mappings parser. The optional name field is read with!isSeparator(peek())and nohasNext()guard, so at end-of-string the parser reads a phantom VLQ (0) and stamps the previousnameIndex's name onto a segment that has none.User-visible effect: with
--enable-source-maps, the bottom global frame of a stack trace inherits the last-named function name. Introduced by #36042 (first released in v15.4.0 / v14.17.1); confirmed absent in v14.17.0.Includes a regression test covering both a nameless trailing segment and a legitimately-named one.
Fixes: #63795