r2336, r2337, r2339, r2390 merge:

bugfixes in error logging:
*) ngx_strerror_r() style and size == 0 bug fix
*) increase ngx_conf_log_error() buffer
*) always log an error code
*) fix segfault on close error
*) compact win32 errno logging

src/core/ngx_conf_file.c

@@ -201,14 +201,14 @@ done:
     if (filename) {
         ngx_free(cf->conf_file->buffer->start);
 
-        cf->conf_file = prev;
-
         if (ngx_close_file(fd) == NGX_FILE_ERROR) {
             ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
                           ngx_close_file_n " %s failed",
                           cf->conf_file->file.name.data);
             return NGX_CONF_ERROR;
         }
+
+        cf->conf_file = prev;
     }
 
     if (rc == NGX_ERROR) {
@@ -853,31 +853,47 @@ void ngx_cdecl
 ngx_conf_log_error(ngx_uint_t level, ngx_conf_t *cf, ngx_err_t err,
     char *fmt, ...)
 {
-    u_char   errstr[NGX_MAX_CONF_ERRSTR], *buf, *last;
+    u_char   errstr[NGX_MAX_CONF_ERRSTR], *p, *last;
     va_list  args;
 
     last = errstr + NGX_MAX_CONF_ERRSTR;
 
     va_start(args, fmt);
-    buf = ngx_vsnprintf(errstr, last - errstr, fmt, args);
+    p = ngx_vsnprintf(errstr, last - errstr, fmt, args);
     va_end(args);
 
-    *buf = '\0';
-
     if (err) {
-        buf = ngx_snprintf(buf, last - buf - 1, " (%d: ", err);
-        buf = ngx_strerror_r(err, buf, last - buf - 1);
-        *buf++ = ')';
-        *buf = '\0';
+
+        if (p > last - 50) {
+
+            /* leave a space for an error code */
+
+            p = last - 50;
+            *p++ = '.';
+            *p++ = '.';
+            *p++ = '.';
+        }
+
+#if (NGX_WIN32)
+        p = ngx_snprintf(p, last - p, ((unsigned) err < 0x80000000)
+                                           ? " (%d: " : " (%Xd: ", err);
+#else
+        p = ngx_snprintf(p, last - p, " (%d: ", err);
+#endif
+
+        p = ngx_strerror_r(err, p, last - p);
+
+        *p++ = ')';
     }
 
     if (cf->conf_file == NULL) {
-        ngx_log_error(level, cf->log, 0, "%s", errstr);
+        ngx_log_error(level, cf->log, 0, "%*s", p - errstr, errstr);
         return;
     }
 
-    ngx_log_error(level, cf->log, 0, "%s in %s:%ui",
-                  errstr, cf->conf_file->file.name.data, cf->conf_file->line);
+    ngx_log_error(level, cf->log, 0, "%*s in %s:%ui",
+                  p - errstr, errstr,
+                  cf->conf_file->file.name.data, cf->conf_file->line);
 }
 
 

src/core/ngx_conf_file.h

@@ -71,7 +71,7 @@
 #define NGX_CONF_MODULE      0x464E4F43  /* "CONF" */
 
 
-#define NGX_MAX_CONF_ERRSTR  256
+#define NGX_MAX_CONF_ERRSTR  1024
 
 
 struct ngx_command_s {

src/core/ngx_log.c

@@ -127,18 +127,10 @@ ngx_log_error_core(ngx_uint_t level, ngx_log_t *log, ngx_err_t err,
         }
 
 #if (NGX_WIN32)
-
-        if ((unsigned) err >= 0x80000000) {
-            p = ngx_snprintf(p, last - p, " (%Xd: ", err);
-
-        } else {
-            p = ngx_snprintf(p, last - p, " (%d: ", err);
-        }
-
+        p = ngx_snprintf(p, last - p, ((unsigned) err < 0x80000000)
+                                           ? " (%d: " : " (%Xd: ", err);
 #else
-
         p = ngx_snprintf(p, last - p, " (%d: ", err);
-
 #endif
 
         p = ngx_strerror_r(err, p, last - p);

src/os/unix/ngx_errno.c

@@ -10,10 +10,11 @@
 
 #if (NGX_HAVE_STRERROR_R)
 
-u_char *ngx_strerror_r(int err, u_char *errstr, size_t size)
+u_char *
+ngx_strerror_r(int err, u_char *errstr, size_t size)
 {
     if (size == 0) {
-        return 0;
+        return errstr;
     }
 
     errstr[0] = '\0';
@@ -32,12 +33,13 @@ u_char *ngx_strerror_r(int err, u_char *errstr, size_t size)
 
 /* Linux strerror_r() */
 
-u_char *ngx_strerror_r(int err, u_char *errstr, size_t size)
+u_char *
+ngx_strerror_r(int err, u_char *errstr, size_t size)
 {
     char  *str;
 
     if (size == 0) {
-        return 0;
+        return errstr;
     }
 
     errstr[0] = '\0';

src/os/win32/ngx_errno.c

@@ -91,7 +91,8 @@ static ngx_str_t  wsa_errors[] = {
 };
 
 
-u_char *ngx_strerror_r(ngx_err_t err, u_char *errstr, size_t size)
+u_char *
+ngx_strerror_r(ngx_err_t err, u_char *errstr, size_t size)
 {
     int        n;
     u_int      len;

src/os/win32/ngx_gui.c

@@ -36,13 +36,8 @@ ngx_message_box(char *title, ngx_uint_t type, ngx_err_t err,
             *p++ = '.';
         }
 
-        if ((unsigned) err >= 0x80000000) {
-            p = ngx_snprintf(p, last - p, " (%Xd: ", err);
-
-        } else {
-            p = ngx_snprintf(p, last - p, " (%d: ", err);
-        }
-
+        p = ngx_snprintf(p, last - p, ((unsigned) err < 0x80000000)
+                                           ? " (%d: " : " (%Xd: ", err);
         p = ngx_strerror_r(err, p, last - p);
 
         if (p < last) {