Fix CID 174276 various malloc()/realloc() failure handling

Have free_paragraphs() explicitly allow paragraphs to be NULL and
have everything use the fail_return which now free()s ret.

src/sbbs3/wordwrap.c

@@ -295,6 +295,9 @@ static void free_paragraphs(struct paragraph *paragraph, int count)
 {
 	int i;
 
+	if (paragraph == NULL)
+		return;
+
 	for(i=0; count == -1 || i<count ;i++) {
 		FREE_AND_NULL(paragraph[i].prefix.bytes);
 		if (count == -1 && paragraph[i].text == NULL)
@@ -351,18 +354,14 @@ static struct paragraph *word_unwrap(char *inbuf, int oldlen, BOOL handle_quotes
 		incol = 0;
 		/* Start of a new paragraph (ie: after a hard CR) */
 		newret = realloc(ret, (paragraph+1) * sizeof(struct paragraph));
-		if (newret == NULL) {
-			free_paragraphs(ret, paragraph);
-			return NULL;
-		}
+		if (newret == NULL)
+			goto fail_return;
 		ret = newret;
 		ret[paragraph].text = (char *)malloc(alloc_len);
 		ret[paragraph].len = 0;
 		ret[paragraph].prefix.bytes = NULL;
-		if (ret[paragraph].text == NULL) {
-			free_paragraphs(ret, paragraph+1);
-			return NULL;
-		}
+		if (ret[paragraph].text == NULL)
+			goto fail_return;
 		ret[paragraph].alloc_size = alloc_len;
 		ret[paragraph].text[0] = 0;
 		if (handle_quotes) {
@@ -468,10 +467,8 @@ static struct paragraph *word_unwrap(char *inbuf, int oldlen, BOOL handle_quotes
 	}
 
 	newret = realloc(ret, (paragraph+1) * sizeof(struct paragraph));
-	if (newret == NULL) {
-		free_paragraphs(ret, paragraph);
-		return NULL;
-	}
+	if (newret == NULL)
+		goto fail_return;
 	ret = newret;
 	memset(&ret[paragraph], 0, sizeof(ret[0]));
 
@@ -479,6 +476,7 @@ static struct paragraph *word_unwrap(char *inbuf, int oldlen, BOOL handle_quotes
 
 fail_return:
 	free_paragraphs(ret, paragraph+1);
+	free(ret);
 	return NULL;
 }