now use mv if rename(2) fails

diff --git a/visudo.c b/visudo.c
index 5a150accc3abc67feb98d0505521fd52a82a84e8..aeba7f2e1e234991eaa1df06bbfd4bcab1b9966d 100644 (file)
--- a/visudo.c
+++ b/visudo.c
@@ -276,17 +276,51 @@ main(argc, argv)
     } while (err_line_no);
 
     /*
-     * once the temporary sudoers file is gramatically correct, we can 
-     * rename it to the real sudoers file.
+     * Once the temporary sudoers file is gramatically correct, we can 
+     * rename it to the real sudoers file.  If the rename(2) fails
+     * we try using mv(1) in case the temp and sudoers files are on
+     * different filesystems.
      */
     if (rename(sudoers_tmp_file, sudoers) != 0) {
+       int status, len;
+       char *tmpbuf;
+
+       /* Print a warning/error */
        (void) fprintf(stderr, "%s: ", Argv[0]);
        perror("rename");
-    } else {
-       if (chmod(sudoers, 0400) != 0)
-           perror("chmod: failed");
-       exit(0);
+
+       /* Allocate just enough space for tmpbuf */
+       len = sizeof(char) * (strlen(_PATH_MV) + strlen(sudoers_tmp_file) +
+           strlen(sudoers) + 4);
+       if ((tmpbuf = (char *) malloc(len)) == NULL) {
+           (void) fprintf(stderr, "%s: cannot allocate memory: ", Argv[0]);
+           perror("");
+           Exit(0);
+       }
+
+       (void) sprintf(tmpbuf, "%s %s %s", _PATH_MV, sudoers_tmp_file, sudoers);
+       status = system(tmpbuf);
+       status = status >> 8;
+       if (status) {
+           (void) fprintf(stderr, "Command failed: '%s', %s unchanged.\n",
+               tmpbuf, sudoers);
+           Exit(0);
+       } else {
+           (void) fprintf(stderr, "Used '%s' instead.\n", tmpbuf);
+       }
+       (void) free(tmpbuf);
     }
+
+    /*
+     * The chmod is a non-fatal error.
+     */
+    if (chmod(sudoers, 0400) != 0) {
+       (void) fprintf(stderr, "%s: Warning, unable to chmod 0400 %s: ",
+           Argv[0], sudoers);
+       perror("");
+    }
+
+    exit(0);
 }