updated: [96fc77b] fixed canonicalize_pathname() breakage: fixed str_move() function (memmove semantics) again

["Sergei Trofimovich" <slyfox inbox ru>]

The following commit has been merged in the master branch:
commit 96fc77bc3ee1f2ae2ae7c0a14d3bf08975b4cb66
Author: Sergei Trofimovich <slyfox inbox ru>
Date:   Sat Feb 7 16:10:33 2009 +0200

    fixed canonicalize_pathname() breakage: fixed str_move() function (memmove semantics) again
    
    This patch reintroduces fix firstly appeared in (and recently broken by mhl revert)
    >   commit e48cb7c89ff3e54de70130a3de2136a9902a023d
    >   Author: Sergei Trofimovich <st anti-virus by>
    >   Date:   Fri Jan 30 09:31:28 2009 +0200
    >
    >        mhl: added mhl_strmove() function (memmove semantics)
    ...
    >            Snippet of man strcpy:
    >       DESCRIPTION
    >               The  strcpy()  function copies the string pointed to by src, including the terminating
    >               null byte ('\0'), to the buffer pointed to by dest.  ___The strings may not overlap___,
    >               and the destination string dest must be  large enough to receive the copy.
    >       We used strcpy to move data chunk in memory: "./foo" -> "foo", etc.
    >
    >       This patch introduces mhl_strmove and fixed canonicalize_pathname.
    
    Signed-off-by: Sergei Trofimovich <slyfox inbox ru>

diff --git a/src/util.h b/src/util.h
index 1ac88dd..e108424 100644
--- a/src/util.h
+++ b/src/util.h
@@ -2,7 +2,8 @@
 #define MC_UTIL_H
 
 #include <sys/types.h>
-
+#include <assert.h>
+#include <string.h>
 
 /* Returns its argument as a "modifiable" string. This function is
  * intended to pass strings to legacy libraries that don't know yet
@@ -263,7 +264,28 @@ char *shell_unescape( const char * );
 char *shell_escape( const char * );
 
 #define str_dup_range(s_start, s_bound) (g_strndup(s_start, s_bound - s_start))
-#define str_move(dest, src) (g_strlcpy(dest,src,strlen(src)))
+
+/*
+ * strcpy is unsafe on overlapping memory areas, so define memmove-alike
+ * string function.
+ * Have sense only when:
+ *  * dest <= src
+ *   AND
+ *  * dest and str are pointers to one object (as Roland Illig pointed).
+ *
+ * We can't use str*cpy funs here:
+ * http://kerneltrap.org/mailarchive/openbsd-misc/2008/5/27/1951294
+ */
+static inline char * str_move(char * dest, const char * src)
+{
+    size_t n;
+
+    assert (dest<=src);
+
+    n = strlen (src) + 1; /* + '\0' */
+
+    return memmove (dest, src, n);
+}
 
 #define MC_PTR_FREE(ptr) do { g_free(ptr); (ptr) = NULL; } while (0)
 

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