write_nondefault_variables must take care to write custom_variable_classes

first; otherwise backends reading the file might reject values of custom
variables.  Per experimentation with auto_explain.

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 62649b8ef42da7ccfcab623cf167b5325149632d..e881746924aba4f949b999b8ae8916c162298184 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.485 2009/01/02 01:16:02 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.486 2009/01/02 02:02:10 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -6677,19 +6677,82 @@ is_newvalue_equal(struct config_generic * record, const char *newvalue)
 #ifdef EXEC_BACKEND
 
 /*
- * This routine dumps out all non-default GUC options into a binary
+ * These routines dump out all non-default GUC options into a binary
  * file that is read by all exec'ed backends.  The format is:
  *
  *     variable name, string, null terminated
  *     variable value, string, null terminated
  *     variable source, integer
  */
+static void
+write_one_nondefault_variable(FILE *fp, struct config_generic *gconf)
+{
+   if (gconf->source == PGC_S_DEFAULT)
+       return;
+
+   fprintf(fp, "%s", gconf->name);
+   fputc(0, fp);
+
+   switch (gconf->vartype)
+   {
+       case PGC_BOOL:
+       {
+           struct config_bool *conf = (struct config_bool *) gconf;
+
+           if (*conf->variable)
+               fprintf(fp, "true");
+           else
+               fprintf(fp, "false");
+       }
+       break;
+
+       case PGC_INT:
+       {
+           struct config_int *conf = (struct config_int *) gconf;
+
+           fprintf(fp, "%d", *conf->variable);
+       }
+       break;
+
+       case PGC_REAL:
+       {
+           struct config_real *conf = (struct config_real *) gconf;
+
+           /* Could lose precision here? */
+           fprintf(fp, "%f", *conf->variable);
+       }
+       break;
+
+       case PGC_STRING:
+       {
+           struct config_string *conf = (struct config_string *) gconf;
+
+           fprintf(fp, "%s", *conf->variable);
+       }
+       break;
+
+       case PGC_ENUM:
+       {
+           struct config_enum *conf = (struct config_enum *) gconf;
+                       
+           fprintf(fp, "%s",
+                   config_enum_lookup_by_value(conf, *conf->variable));
+       }
+       break;
+   }
+
+   fputc(0, fp);
+
+   fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
+}
+
 void
 write_nondefault_variables(GucContext context)
 {
-   int         i;
    int         elevel;
    FILE       *fp;
+   struct config_generic *cvc_conf;
+   int         i;
 
    Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
 
@@ -6708,66 +6771,20 @@ write_nondefault_variables(GucContext context)
        return;
    }
 
+   /*
+    * custom_variable_classes must be written out first; otherwise we might
+    * reject custom variable values while reading the file.
+    */
+   cvc_conf = find_option("custom_variable_classes", false, ERROR);
+   if (cvc_conf)
+       write_one_nondefault_variable(fp, cvc_conf);
+
    for (i = 0; i < num_guc_variables; i++)
    {
        struct config_generic *gconf = guc_variables[i];
 
-       if (gconf->source != PGC_S_DEFAULT)
-       {
-           fprintf(fp, "%s", gconf->name);
-           fputc(0, fp);
-
-           switch (gconf->vartype)
-           {
-               case PGC_BOOL:
-                   {
-                       struct config_bool *conf = (struct config_bool *) gconf;
-
-                       if (*conf->variable == 0)
-                           fprintf(fp, "false");
-                       else
-                           fprintf(fp, "true");
-                   }
-                   break;
-
-               case PGC_INT:
-                   {
-                       struct config_int *conf = (struct config_int *) gconf;
-
-                       fprintf(fp, "%d", *conf->variable);
-                   }
-                   break;
-
-               case PGC_REAL:
-                   {
-                       struct config_real *conf = (struct config_real *) gconf;
-
-                       /* Could lose precision here? */
-                       fprintf(fp, "%f", *conf->variable);
-                   }
-                   break;
-
-               case PGC_STRING:
-                   {
-                       struct config_string *conf = (struct config_string *) gconf;
-
-                       fprintf(fp, "%s", *conf->variable);
-                   }
-                   break;
-
-               case PGC_ENUM:
-                   {
-                       struct config_enum *conf = (struct config_enum *) gconf;
-                       
-                       fprintf(fp, "%s", config_enum_lookup_by_value(conf, *conf->variable));
-                   }
-                   break;
-           }
-
-           fputc(0, fp);
-
-           fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
-       }
+       if (gconf != cvc_conf)
+           write_one_nondefault_variable(fp, gconf);
    }
 
    if (FreeFile(fp))