lib: If log prefix update can't be sent to log, exit with FATAL_LOGERROR

diff --git a/src/lib/failures.c b/src/lib/failures.c
index 2273bd4b1ca6aacdec7b52c82403f29ffc99f2c9..083e3b8fb2cc3d15201c15e5c1893ee08b881152 100644 (file)
--- a/src/lib/failures.c
+++ b/src/lib/failures.c
@@ -61,7 +61,7 @@ static bool failure_ignore_errors = FALSE, log_prefix_sent = FALSE;
 static bool coredump_on_error = FALSE;
 static void log_timestamp_add(const struct failure_context *ctx, string_t *str);
 static void log_prefix_add(const struct failure_context *ctx, string_t *str);
-static void i_failure_send_option_forced(const char *key, const char *value);
+static int i_failure_send_option_forced(const char *key, const char *value);
 static int internal_send_split(string_t *full_str, size_t prefix_len);
 
 static string_t * ATTR_FORMAT(3, 0) default_format(const struct failure_context *ctx,
@@ -191,8 +191,13 @@ static string_t * ATTR_FORMAT(3, 0) internal_format(const struct failure_context
                if (ctx->log_prefix_type_pos != 0)
                        log_type |= LOG_TYPE_FLAG_PREFIX_LEN;
        } else if (!log_prefix_sent && log_prefix != NULL) {
+               if (i_failure_send_option_forced("prefix", log_prefix) < 0) {
+                       /* Failed to write log prefix. The log message writing
+                          would likely fail as well, but don't even try since
+                          the log prefix would be wrong. */
+                       return NULL;
+               }
                log_prefix_sent = TRUE;
-               i_failure_send_option_forced("prefix", log_prefix);
        }
 
        str = t_str_new(128);
@@ -266,7 +271,8 @@ static int common_handler(const struct failure_context *ctx,
 
        T_BEGIN {
                string_t *str = failure_handler.v->format(ctx, &prefix_len, format, args);
-               ret = failure_handler.v->write(ctx->type, str, prefix_len);
+               ret = str == NULL ? -1 :
+                       failure_handler.v->write(ctx->type, str, prefix_len);
        } T_END;
 
        if (ret < 0 && failure_ignore_errors)
@@ -720,20 +726,20 @@ void i_set_failure_file(const char *path, const char *prefix)
        i_set_debug_handler(default_error_handler);
 }
 
-static void i_failure_send_option_forced(const char *key, const char *value)
+static int i_failure_send_option_forced(const char *key, const char *value)
 {
        const char *str;
 
        str = t_strdup_printf("\001%c%s %s=%s\n", LOG_TYPE_OPTION+1,
                              my_pid, key, value);
-       (void)log_fd_write(STDERR_FILENO, (const unsigned char *)str,
-                          strlen(str));
+       return log_fd_write(STDERR_FILENO, (const unsigned char *)str,
+                           strlen(str));
 }
 
 static void i_failure_send_option(const char *key, const char *value)
 {
        if (error_handler == i_internal_error_handler)
-               i_failure_send_option_forced(key, value);
+               (void)i_failure_send_option_forced(key, value);
 }
 
 void i_set_failure_prefix(const char *prefix_fmt, ...)