* lib-src/emacsclient.c (send_to_emacs): Avoid invalid strcpy

upon partial send.

Fixes: debbugs:11374

diff --git a/lib-src/ChangeLog b/lib-src/ChangeLog
index d225b77f156cca64fd079ce76128ce9bb22c27a9..007a365708c7c32f1416c3181c1af1e02c661eea 100644 (file)
--- a/lib-src/ChangeLog
+++ b/lib-src/ChangeLog
@@ -1,3 +1,8 @@
+2012-05-02  Jim Meyering  <jim@meyering.net>
+
+       * emacsclient.c (send_to_emacs): Avoid invalid strcpy upon partial
+       send (Bug#11374).
+
 2012-04-29  Andreas Schwab  <schwab@linux-m68k.org>
 
        * make-docfile.c (scan_lisp_file) [DEBUG]: Also skip if and

diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c
index ea55398306b016655b7a81ae779c5682bc0f6a99..d8e9e256584db7ad2ef0f12e7cc545f71be17147 100644 (file)
--- a/lib-src/emacsclient.c
+++ b/lib-src/emacsclient.c
@@ -119,6 +119,8 @@ char *(getcwd) (char *, size_t);
 # define IF_LINT(Code) /* empty */
 #endif
 
+#define min(x, y) (((x) < (y)) ? (x) : (y))
+
 \f
 /* Name used to invoke this program.  */
 const char *progname;
@@ -783,33 +785,35 @@ sock_err_message (const char *function_name)
 static void
 send_to_emacs (HSOCKET s, const char *data)
 {
-  while (data)
+  size_t dlen;
+
+  if (!data)
+    return;
+
+  dlen = strlen (data);
+  while (*data)
     {
-      size_t dlen = strlen (data);
-      if (dlen + sblen >= SEND_BUFFER_SIZE)
-       {
-         int part = SEND_BUFFER_SIZE - sblen;
-         strncpy (&send_buffer[sblen], data, part);
-         data += part;
-         sblen = SEND_BUFFER_SIZE;
-       }
-      else if (dlen)
-       {
-         strcpy (&send_buffer[sblen], data);
-         data = NULL;
-         sblen += dlen;
-       }
-      else
-       break;
+      size_t part = min (dlen, SEND_BUFFER_SIZE - sblen);
+      memcpy (&send_buffer[sblen], data, part);
+      data += part;
+      sblen += part;
 
       if (sblen == SEND_BUFFER_SIZE
          || (sblen > 0 && send_buffer[sblen-1] == '\n'))
        {
          int sent = send (s, send_buffer, sblen, 0);
+         if (sent < 0)
+           {
+             message (TRUE, "%s: failed to send %d bytes to socket: %s\n",
+                      progname, sblen, strerror (errno));
+             fail ();
+           }
          if (sent != sblen)
-           strcpy (send_buffer, &send_buffer[sent]);
+           memmove (send_buffer, &send_buffer[sent], sblen - sent);
          sblen -= sent;
        }
+
+      dlen -= part;
     }
 }