reachableroots: reduce nesting level by jumping to next iteration by continue

This can eliminate lines over 80 columns. No code change except for the
outermost "if" condition.

mercurial/parsers.c

@@ -1197,19 +1197,19 static PyObject *reachableroots(indexObj
 		Py_DECREF(val);
 
 		/* Add its parents to the list of nodes to visit */
-		if (revnum != -1) {
+		if (revnum == -1)
+			continue;
 			r = index_get_parents(self, revnum, parents, (int)len - 1);
 			if (r < 0)
 				goto bail;
-
 			for (i = 0; i < 2; i++) {
-				if (seen[parents[i] + 1] == 0 && parents[i] >= minroot) {
+			if (seen[parents[i] + 1] == 0
+			    && parents[i] >= minroot) {
 					tovisit[lentovisit++] = parents[i];
 					seen[parents[i] + 1] = 1;
 				}
 			}
 		}
-	}
 
 	/* Find all the nodes in between the roots we found and the heads
 	 * and add them to the reachable set */
@@ -1218,9 +1218,11 static PyObject *reachableroots(indexObj
 		if (minidx < 0)
 			minidx = 0;
 		for (i = minidx; i < len; i++) {
-			if (seen[i + 1] == 1) {
+			if (seen[i + 1] != 1)
+				continue;
 				r = index_get_parents(self, i, parents, (int)len - 1);
-				/* Corrupted index file, error is set from index_get_parents */
+			/* Corrupted index file, error is set from
+			 * index_get_parents */
 				if (r < 0)
 					goto bail;
 				for (k = 0; k < 2; k++) {
@@ -1238,7 +1240,6 static PyObject *reachableroots(indexObj
 				}
 			}
 		}
-	}
 
 	free(seen);
 	free(tovisit);