Save errno to prevent debugs from clobbering it

diff --git a/src/debug.cc b/src/debug.cc
index 5d573a8abb89644c5c7f0b5e7b79a9cc9586dd75..85a03772d41008e579dfa064169ba522ec3df9cc 100644 (file)
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -470,7 +470,8 @@ _db_rotate_log(void)
 #endif
         errno = 0;
         if (rename(from, to) == -1) {
-            debugs(0, DBG_IMPORTANT, "log rotation failed: " << xstrerror());
+            const auto saved_errno = errno;
+            debugs(0, DBG_IMPORTANT, "log rotation failed: " << xstrerr(saved_errno));
         }
     }