Replace strcat with strlcat

src/util/common.c

@@ -461,9 +461,10 @@ char *expand_tilde(const char *s)
 {
     const gchar *home = g_get_home_dir();
     if (home && (strcmp(s, "~") == 0 || strstr(s, "~/") == s)) {
-        char *result = calloc(strlen(home) + strlen(s), 1);
-        strcat(result, home);
-        strcat(result, s + 1);
+        size_t buf_size = strlen(home) + strlen(s);
+        char *result = calloc(buf_size, 1);
+        strlcat(result, home, buf_size);
+        strlcat(result, s + 1, buf_size);
         return result;
     } else {
         return strdup(s);
@@ -476,14 +477,16 @@ char *contract_tilde(const char *s)
     if (!home)
         return strdup(s);
 
-    char *home_slash = calloc(strlen(home) + 2, 1);
-    strcat(home_slash, home);
-    strcat(home_slash, "/");
+    size_t buf_size = strlen(home) + 2;
+    char *home_slash = calloc(buf_size, 1);
+    strlcat(home_slash, home, buf_size);
+    strlcat(home_slash, "/", buf_size);
 
     if ((strcmp(s, home) == 0 || strstr(s, home_slash) == s)) {
-        char *result = calloc(strlen(s) - strlen(home) + 2, 1);
-        strcat(result, "~");
-        strcat(result, s + strlen(home));
+        size_t buf_size = strlen(s) - strlen(home) + 2;
+        char *result = calloc(buf_size, 1);
+        strlcat(result, "~", buf_size);
+        strlcat(result, s + strlen(home), buf_size);
         free(home_slash);
         return result;
     } else {

src/util/common.h

@@ -13,6 +13,7 @@
 #include <pango/pangocairo.h>
 #include "area.h"
 #include "colors.h"
+#include "strlcat.h"
 
 #define MAX3(a, b, c) MAX(MAX(a, b), c)
 #define MIN3(a, b, c) MIN(MIN(a, b), c)

src/util/strlcat.c

@@ -0,0 +1,59 @@
+/*	$NetBSD: strlcat.c,v 1.4 2005/05/16 06:55:48 lukem Exp $	*/
+/*	from	NetBSD: strlcat.c,v 1.16 2003/10/27 00:12:42 lukem Exp	*/
+/*	from OpenBSD: strlcat.c,v 1.10 2003/04/12 21:56:39 millert Exp	*/
+
+/*
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
+ * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "strlcat.h"
+
+/*
+ * Appends src to string dst of size siz (unlike strncat, siz is the
+ * full size of dst, not space left).  At most siz-1 characters
+ * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
+ * Returns strlen(src) + MIN(siz, strlen(initial dst)).
+ * If retval >= siz, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t siz)
+{
+    char *d = dst;
+    const char *s = src;
+    size_t n = siz;
+    size_t dlen;
+
+    /* Find the end of dst and adjust bytes left but don't go past end */
+    while (n-- != 0 && *d != '\0')
+        d++;
+    dlen = d - dst;
+    n = siz - dlen;
+
+    if (n == 0)
+        return(dlen + strlen(s));
+    while (*s != '\0') {
+        if (n != 1) {
+            *d++ = *s;
+            n--;
+        }
+        s++;
+    }
+    *d = '\0';
+
+    return(dlen + (s - src));	/* count does not include NUL */
+}

src/util/strlcat.h

@@ -0,0 +1,16 @@
+#ifndef STRLCAT_H
+#define STRLCAT_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/*
+ * Appends src to string dst of size siz (unlike strncat, siz is the
+ * full size of dst, not space left).  At most siz-1 characters
+ * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
+ * Returns strlen(src) + MIN(siz, strlen(initial dst)).
+ * If retval >= siz, truncation occurred.
+ */
+size_t strlcat(char *dst, const char *src, size_t siz);
+
+#endif