On Wed, Dec 07, 2022 at 05:52:04AM +0100, Ævar Arnfjörð Bjarmason wrote: > > On Mon, Dec 05 2022, Lars Kellogg-Stedman wrote: > > > When the -L argument to "git log" is passed the degenerate regular > > expression "$" (as in "-L :$:line-range.c"), this results in an > > infinite loop in find_funcname_matching_regexp() (the function > > iterates through the file correctly, but when it reaches the end of > > the file it matches $ against the empty string, "", and at that points > > loops forever). > > > > Modify the loop condition from while (1) to while (*start) so that the > > loop exits when start is the empty string. In this case, "git log" exits > > with the error: > > > > fatal: -L parameter '$' starting at line 1: no match > > > > Originally reported in <https://stackoverflow.com/q/74690545/147356>. > > > > Signed-off-by: Lars Kellogg-Stedman <lars@xxxxxxxxxx> > > --- > > line-range.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/line-range.c b/line-range.c > > index 955a8a9535..bdcb810485 100644 > > --- a/line-range.c > > +++ b/line-range.c > > @@ -135,7 +135,7 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char > > { > > int reg_error; > > regmatch_t match[1]; > > - while (1) { > > + while (*start) { > > const char *bol, *eol; > > reg_error = regexec(regexp, start, 1, match, 0); > > if (reg_error == REG_NOMATCH) > > @@ -161,6 +161,8 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char > > return bol; > > start = eol; > > } > > + > > + return NULL; > > } > > > > static const char *parse_range_funcname( > > We really should fix this, but why not just count this as a match, > rather than erroring out? > > That we're mixing up whether '$' always matches here with our iteration > loop is our own internal bug, we shouldn't error out on a '$'. It's just > a regex that happens to match everything. Indeed. The description of '-L...' in the manpage of 'git log' (and 'blame') states: If :<funcname> is given in place of <start> and <end>, it is a regular expression that denotes the range from the first funcname line that matches <funcname>, up to the next funcname line. So, if we use '-L' with a funcname regex that matches every line, be it '$', '^' or '.*', then this would mean that it should denote the range from the first funcname line in that file to the second.
