Fix MySQL lexer edge cases - #460
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The final backslash-stripping step used preg_replace() with the "u" (UTF-8) modifier. That modifier makes PCRE validate the whole subject as UTF-8 and return null on the first invalid byte; since get_value() is typed ": string", the null turned into a fatal TypeError. MySQL string literals may legitimately carry non-UTF-8 bytes (binary or other-charset payloads), and the lexer scans them at the byte level, so reading the value of such a literal crashed. Switch the modifier to "s" (DOTALL). A byte-wise strip is binary-safe, yields identical results for valid UTF-8 (no continuation byte is a backslash), and additionally handles a backslash preceding a newline byte.
When resolving a function keyword (SYM_FN), the lexer peeks for a following "("
and, under SQL_MODE_IGNORE_SPACE, skips intervening whitespace first. It skipped
by advancing bytes_already_read and never restored it. When no "(" followed, the
keyword was emitted as an IDENTIFIER whose length — derived from
bytes_already_read in produce() — now covered the trailing whitespace, so the
extracted value was e.g. "COUNT " instead of "COUNT". Under this ANSI-style mode
a column or table named after a function would resolve to the wrong identifier.
Peek with a local index instead of mutating bytes_already_read, so the token's
byte range ends at the keyword and the next scan consumes the whitespace.
read_mysql_comment() read at most five version digits, so a six-digit MMmmrr version comment — added in MySQL 8.4 — was misparsed: /*!100000 ... */ gated as version 10000 instead of 100000, and the sixth digit of /*!080400 ... */ leaked into the comment body as SQL. Mirror MySQL's own lexer rule (sql/sql_lex.cc): the first five characters must be digits; a sixth digit immediately followed by whitespace extends the version to six digits; otherwise the version stays five digits and any extra is content.
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Summary
IGNORE_SPACElookahead whitespace outside function-name token rangesWhy
These cases currently produce incorrect token values or ranges, or fail to recognize version comments supported by current MySQL releases.
This PR is stacked on #452, which already contains the quoted-identifier backslash fix that was previously part of this branch.
Validation
composer testinpackages/mysql-parser— 142 tests, 1,225,624 assertionsgit diff --check