bc: fixes to bugs found while testing 64-bit build

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 13 insertions, 8 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 20ce497dd..57ae52ce7 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -2690,12 +2690,11 @@ static void bc_lex_whitespace(BcLex *l)
 static BC_STATUS zbc_lex_number(BcLex *l, char start)
 {
         const char *buf = l->buf + l->i;
-        size_t len, bslashes, i, ccnt;
+        size_t len, i, ccnt;
         bool pt;
 
         pt = (start == '.');
         l->t.t = BC_LEX_NUMBER;
-        bslashes = 0;
         ccnt = i = 0;
         for (;;) {
                 char c = buf[i];
@@ -2703,26 +2702,31 @@ static BC_STATUS zbc_lex_number(BcLex *l, char start)
                         break;
                 if (c == '\\' && buf[i + 1] == '\n') {
                         i += 2;
-                        bslashes++;
+                        //number_of_backslashes++ - see comment below
                         continue;
                 }
                 if (!isdigit(c) && (c < 'A' || c > 'F')) {
                         if (c != '.') break;
                         // if '.' was already seen, stop on second one:
                         if (pt) break;
-                        pt = 1;
+                        pt = true;
                 }
                 // buf[i] is one of "0-9A-F."
                 i++;
                 if (c != '.')
                         ccnt = i;
         }
-        //i is buf[i] index of the first not-yet-parsed char
+        //ccnt is the number of chars in the number string, excluding possible
+        //trailing "[\<newline>].[\<newline>]" (with any number of \<NL> repetitions).
+        //i is buf[i] index of the first not-yet-parsed char after that.
         l->i += i;
 
-        //ccnt is the number of chars in the number string, excluding possible
-        //trailing "." and possible following trailing "\<newline>"(s).
-        len = ccnt - bslashes * 2 + 1; // +1 byte for NUL termination
+        // This might overestimate the size, if there are "\<NL>"'s
+        // in the number. Subtracting number_of_backslashes*2 correctly
+        // is not that easy: consider that in the case of "NNN.\<NL>"
+        // loop above will count "\<NL>" before it realizes it is not
+        // in fact *inside* the number:
+        len = ccnt + 1; // +1 byte for NUL termination
 
         // This check makes sense only if size_t is (much) larger than BC_MAX_NUM.
         if (SIZE_MAX > (BC_MAX_NUM | 0xff)) {
@@ -2979,6 +2983,7 @@ static BC_STATUS zbc_lex_identifier(BcLex *l)
         }
 
         bc_lex_name(l);
+        s = BC_STATUS_SUCCESS;
 
         if (l->t.v.len > 2) {
                 // Prevent this: