https://github.com/cyrusimap/cyrus-imapd/issues/2850

filled Argv[0] by '\0' instead of ' ' by default

used memset() instead of loop (better optimized by the compiler)

diff --git a/imap/setproctitle.c b/imap/setproctitle.c

index 4eb2b3139..3f5fb4614 100644

--- a/imap/setproctitle.c

+++ b/imap/setproctitle.c

@@ -196,7 +196,7 @@ typedef unsigned int    *pt_entry_t;

 # endif

 # ifndef SPT_PADCHAR

-#  define SPT_PADCHAR   ' '

+#  define SPT_PADCHAR   '\0'

 # endif

 # ifndef SPT_BUFSIZE

@@ -278,10 +278,9 @@ setproctitle(const char *fmt __attribute__((__unused__)), ...)

                 i = LastArgv - Argv[0] - 2;

                 buf[i] = '\0';

         }

+        memset(Argv[0], SPT_PADCHAR, LastArgv - Argv[0]);

         (void) strcpy(Argv[0], buf);

-        p = &Argv[0][i];

-        while (p < LastArgv)

-                *p++ = SPT_PADCHAR;

+

         Argv[1] = NULL;

 #  endif

 # endif /* SPT_TYPE != SPT_NONE */