[svn] Fix a possible race condition when opening files.

[wget] / src / ftp.c

diff --git a/src/ftp.c b/src/ftp.c
index e65f8284dccae3a3d835f41410b37817cb95e2dd..c1e2d002c7cd7244e9032aab07385b6f29a4cb4f 100644 (file)
--- a/src/ftp.c
+++ b/src/ftp.c
@@ -953,10 +953,30 @@ Error in server response, closing control connection.\n"));
       mkalldirs (con->target);
       if (opt.backups)
        rotate_backups (con->target);
-      /* #### Is this correct? */
-      chmod (con->target, 0600);
 
-      fp = fopen (con->target, restval ? "ab" : "wb");
+      if (restval)
+       fp = fopen (con->target, "ab");
+      else if (opt.noclobber || opt.always_rest || opt.timestamping || opt.dirstruct
+              || opt.output_document)
+       fp = fopen (con->target, "wb");
+      else
+       {
+         fp = fopen_excl (con->target, 0);
+         if (!fp && errno == EEXIST)
+           {
+             /* We cannot just invent a new name and use it (which is
+                what functions like unique_create typically do)
+                because we told the user we'd use this name.
+                Instead, return and retry the download.  */
+             logprintf (LOG_NOTQUIET, _("%s has sprung into existence.\n"),
+                        con->target);
+             fd_close (csock);
+             con->csock = -1;
+             fd_close (dtsock);
+             fd_close (local_sock);
+             return FOPEN_EXCL_ERR;
+           }
+       }
       if (!fp)
        {
          logprintf (LOG_NOTQUIET, "%s: %s\n", con->target, strerror (errno));
@@ -1219,8 +1239,16 @@ ftp_loop_internal (struct url *u, struct fileinfo *f, ccon *con)
        case CONSOCKERR: case CONERROR: case FTPSRVERR: case FTPRERR:
        case WRITEFAILED: case FTPUNKNOWNTYPE: case FTPSYSERR:
        case FTPPORTERR: case FTPLOGREFUSED: case FTPINVPASV:
+       case FOPEN_EXCL_ERR:
          printwhat (count, opt.ntry);
          /* non-fatal errors */
+         if (err == FOPEN_EXCL_ERR)
+           {
+             /* Re-determine the file name. */
+             xfree_null (con->target);
+             con->target = url_file_name (u);
+             locf = con->target;
+           }
          continue;
          break;
        case FTPRETRINT: