[Rpm-maint] [rpm-software-management/rpm] Use int64_t for lengths (#1492)

[Panu Matilainen]

@pmatilai commented on this pull request.



> @@ -467,15 +468,14 @@ static int dataLength(rpm_tagtype_t type, rpm_constdata_t p, rpm_count_t count,
 	break;
 
     default:
-	if (typeSizes[type] == -1)
-	    return -1;
-	length = typeSizes[(type & 0xf)] * count;
-	if (length < 0 || (se && (s + length) > se))
+	/* this won’t overflow, since ‘long_count’ is 64-bit */
+	length = typeSizes[type] * long_count;
+	if (length <= 0 || (se && length > se - s))

I don't see a need for an extra variable. You could just assign to length and multiply, or make eg typeSizes int64 type (and/or count itself for that matter)

Note that this ends up removing an old safety feature in the code, ie that `(type & 0xf)` ensures that we'll never access typeSizes out of bounds. Only there was that redundant `== -1` check before it, making it moot :facepalm: 

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