Split code to generate "rwx-----" strings into lib/permstring.c so it

[rsync/rsync.git] / log.c

diff --git a/log.c b/log.c
index 64e97b9..3b53a9a 100644 (file)
--- a/log.c
+++ b/log.c
@@ -289,7 +289,31 @@ void rprintf(enum logcode code, const char *format, ...)
        len = vsnprintf(buf, sizeof(buf), format, ap);
        va_end(ap);
 
-       if (len > sizeof(buf)-1) exit_cleanup(RERR_MESSAGEIO);
+       /* Deal with buffer overruns.  Instead of panicking, just
+        * truncate the resulting string.  Note that some vsnprintf()s
+        * return -1 on truncation, e.g., glibc 2.0.6 and earlier. */
+       if (len > sizeof(buf)-1  ||  len < 0) {
+               const char ellipsis[] = "[...]";
+
+               /* Reset length, and zero-terminate the end of our buffer */
+               len = sizeof(buf)-1;
+               buf[len] = '\0';
+
+               /* Copy the ellipsis to the end of the string, but give
+                * us one extra character:
+                *
+                *                  v--- null byte at buf[sizeof(buf)-1]
+                *        abcdefghij0
+                *     -> abcd[...]00  <-- now two null bytes at end
+                *
+                * If the input format string has a trailing newline,
+                * we copy it into that extra null; if it doesn't, well,
+                * all we lose is one byte.  */
+               strncpy(buf+len-sizeof(ellipsis), ellipsis, sizeof(ellipsis));
+               if (format[strlen(format)-1] == '\n') {
+                       buf[len-1] = '\n';
+               }
+       }
 
        rwrite(code, buf, len);
 }