When we are parsing an integer or unsigned long, we use
the strto*max functions, which properly set errno to ERANGE
if we get a large value. However, we also do further range
checks after applying our multiplication factor, but do not
set ERANGE. This means that a caller cannot tell if an error
was caused by ERANGE or if the input was simply not a valid
number.
This patch teaches git_parse_signed and git_parse_unsigned
reliably set ERANGE for range errors, and EINVAL for other
errors.
Signed-off-by: Jeff King <p...@peff.net>
---
I'm a little iffy on using errno like this. The "normal" way in git
would be to return an enum like:
enum config_parse_error {
CONFIG_PARSE_SUCCESS = 0,
CONFIG_PARSE_RANGE = -1,
CONFIG_PARSE_INVALID_UNIT = -2
};
But that would be changing the return semantics of git_parse_ulong
(which currently is "0" for fail, "1" for success) without changing its
signature. I figured this was the path of least resistance since we
already get ERANGE out of strtoimax, but I'm happy to switch it, too.
config.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/config.c b/config.c
index 0a65ac2..7332b06 100644
--- a/config.c
+++ b/config.c
@@ -480,16 +480,21 @@ static int git_parse_signed(const char *value, intmax_t
*ret, intmax_t max)
val = strtoimax(value, &end, 0);
if (errno == ERANGE)
return 0;
- if (!parse_unit_factor(end, &factor))
+ if (!parse_unit_factor(end, &factor)) {
+ errno = EINVAL;
return 0;
+ }
uval = abs(val);
uval *= factor;
- if (uval > max || abs(val) > uval)
+ if (uval > max || abs(val) > uval) {
+ errno = ERANGE;
return 0;
+ }
val *= factor;
*ret = val;
return 1;
}
+ errno = EINVAL;
return 0;
}
@@ -505,13 +510,18 @@ int git_parse_unsigned(const char *value, uintmax_t *ret,
uintmax_t max)
if (errno == ERANGE)
return 0;
oldval = val;
- if (!parse_unit_factor(end, &val))
+ if (!parse_unit_factor(end, &val)) {
+ errno = EINVAL;
return 0;
- if (val > max || oldval > val)
+ }
+ if (val > max || oldval > val) {
+ errno = ERANGE;
return 0;
+ }
*ret = val;
return 1;
}
+ errno = EINVAL;
return 0;
}
--
1.8.4.2.g87d4a77
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