comment can't be read back
A change to the lexer in 5.1 caused slash-asterisk-bang-version
sections to be terminated early if there exists a slash-asterisk-
style comment inside it. Nesting comments is usually illegal,
but we rely on versioned comment blocks in mysqldump, and the
contents of those sections must be allowed to have comments.
The problem was that when encountering open-comment tokens and
consuming -or- passing through the contents, the "in_comment"
state at the end was clobbered with the not-in-a-comment value,
regardless of whether we were in a comment before this or not.
So, """/*!VER one /* two */ three */""" would lose its in-comment
state between "two" and "three". Save the echo and in-comment
state, and restore it at the end of the comment if we consume a
comment.
enabled)
Before this fix, the lexer and parser would treat the ';' character as a
different token (either ';' or END_OF_INPUT), based on convoluted logic,
which failed in simple cases where a stored procedure is implemented as a
single statement, and used in a multi query.
With this fix:
- the character ';' is always parsed as a ';' token in the lexer,
- parsing multi queries is implemented in the parser, in the 'query:' rules,
- the value of thd->client_capabilities, which is the capabilities
negotiated between the client and the server during bootstrap,
is immutable and not arbitrarily modified during parsing (which was the
root cause of the bug)
