patch 9.0.2114: overflow detection not accurate when adding digits
Problem: overflow detection not accurate when adding digits
Solution: Use a helper function
Use a helper function to better detect overflows before adding integer
digits to a long or an integer variable respectively. Signal the
overflow to the caller function.
closes: #13539
Signed-off-by: Christian Brabandt <cb@256bit.org>
Signed-off-by: Michael Henry <vim@drmikehenry.com>
Signed-off-by: Ernie Rael <errael@raelity.com>
diff --git a/src/misc1.c b/src/misc1.c
index 5f9828e..dc0deae 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -975,9 +975,8 @@
c = safe_vgetc();
if (VIM_ISDIGIT(c))
{
- if (n > INT_MAX / 10)
+ if (vim_append_digit_int(&n, c - '0') == FAIL)
return 0;
- n = n * 10 + c - '0';
msg_putchar(c);
++typed;
}
@@ -2817,3 +2816,25 @@
restore_v_event(v_event, &save_v_event);
#endif
}
+
+// For overflow detection, add a digit safely to an int value.
+ int
+vim_append_digit_int(int *value, int digit)
+{
+ int x = *value;
+ if (x > ((INT_MAX - digit) / 10))
+ return FAIL;
+ *value = x * 10 + digit;
+ return OK;
+}
+
+// For overflow detection, add a digit safely to a long value.
+ int
+vim_append_digit_long(long *value, int digit)
+{
+ long x = *value;
+ if (x > ((LONG_MAX - (long)digit) / 10))
+ return FAIL;
+ *value = x * 10 + (long)digit;
+ return OK;
+}