Merging r4013, r4200:

error_log related fixes:

*) Complain on invalid log levels.

   Previously only first log level was required to be correct, while
   error_log directive in fact accepts list of levels (e.g. one may
   specify "error_log ... debug_core debug_http;").  This resulted
   in (avoidable) wierd behaviour on missing semicolon after error_log
   directive, e.g.

       error_log /path/to/log info
       index index.php;

   silently skipped index directive and it's arguments (trying to
   interpret them as log levels without checking to be correct).

*) Fixed configuration summary and manpage contents for the special
   --error-log-path=stderr case.

auto/install

@@ -53,7 +53,7 @@ esac
 
 
 case ".$NGX_ERROR_LOG_PATH" in
-    ./*)
+    ./* | .)
     ;;
 
     *)
@@ -78,7 +78,7 @@ manpage:
 	sed -e "s|%%PREFIX%%|$NGX_PREFIX|" \\
 		-e "s|%%PID_PATH%%|$NGX_PID_PATH|" \\
 		-e "s|%%CONF_PATH%%|$NGX_CONF_PATH|" \\
-		-e "s|%%ERROR_LOG_PATH%%|$NGX_ERROR_LOG_PATH|" \\
+		-e "s|%%ERROR_LOG_PATH%%|${NGX_ERROR_LOG_PATH:-stderr}|" \\
 		< man/nginx.8 > $NGX_OBJS/nginx.8
 
 install:	$NGX_OBJS${ngx_dirsep}nginx${ngx_binext} \
@@ -137,7 +137,7 @@ install:	$NGX_OBJS${ngx_dirsep}nginx${ngx_binext} \
 END
 
 
-if test -n "\$(DESTDIR)$NGX_ERROR_LOG_PATH"; then
+if test -n "$NGX_ERROR_LOG_PATH"; then
     cat << END                                                >> $NGX_MAKEFILE
 
 	test -d '\$(DESTDIR)`dirname "$NGX_ERROR_LOG_PATH"`' || \

src/core/ngx_log.c

@@ -369,12 +369,13 @@ ngx_log_create(ngx_cycle_t *cycle, ngx_str_t *name)
 char *
 ngx_log_set_levels(ngx_conf_t *cf, ngx_log_t *log)
 {
-    ngx_uint_t   i, n, d;
+    ngx_uint_t   i, n, d, found;
     ngx_str_t   *value;
 
     value = cf->args->elts;
 
     for (i = 2; i < cf->args->nelts; i++) {
+        found = 0;
 
         for (n = 1; n <= NGX_LOG_DEBUG; n++) {
             if (ngx_strcmp(value[i].data, err_levels[n].data) == 0) {
@@ -387,7 +388,8 @@ ngx_log_set_levels(ngx_conf_t *cf, ngx_log_t *log)
                 }
 
                 log->log_level = n;
-                continue;
+                found = 1;
+                break;
             }
         }
 
@@ -401,11 +403,13 @@ ngx_log_set_levels(ngx_conf_t *cf, ngx_log_t *log)
                 }
 
                 log->log_level |= d;
+                found = 1;
+                break;
             }
         }
 
 
-        if (log->log_level == 0) {
+        if (!found) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                "invalid log level \"%V\"", &value[i]);
             return NGX_CONF_ERROR;