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

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

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 20ce497ddc10d07036042c98f3c11c6220698293..57ae52ce765e00e58c975dffe4cb0f8ecaf3410c 100644 (file)
--- 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: