psql-vars-init-v1.patch

diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 0574b5b..631b3f6 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -166,14 +166,6 @@ main(int argc, char *argv[])
 
 	SetVariable(pset.vars, "VERSION", PG_VERSION_STR);
 
-	/* Default values for variables */
-	SetVariableBool(pset.vars, "AUTOCOMMIT");
-	SetVariable(pset.vars, "VERBOSITY", "default");
-	SetVariable(pset.vars, "SHOW_CONTEXT", "errors");
-	SetVariable(pset.vars, "PROMPT1", DEFAULT_PROMPT1);
-	SetVariable(pset.vars, "PROMPT2", DEFAULT_PROMPT2);
-	SetVariable(pset.vars, "PROMPT3", DEFAULT_PROMPT3);
-
 	parse_psql_options(argc, argv, &options);
 
 	/*
@@ -785,6 +777,11 @@ showVersion(void)
 static bool
 autocommit_hook(const char *newval)
 {
+	if (newval == NULL)
+	{
+		psql_error("built-in variable %s cannot be unset.\n", "AUTOCOMMIT");
+		return false;
+	}
 	return ParseVariableBool(newval, "AUTOCOMMIT", &pset.autocommit);
 }
 
@@ -1002,20 +999,20 @@ EstablishVariableSpace(void)
 {
 	pset.vars = CreateVariableSpace();
 
-	SetVariableAssignHook(pset.vars, "AUTOCOMMIT", autocommit_hook);
-	SetVariableAssignHook(pset.vars, "ON_ERROR_STOP", on_error_stop_hook);
-	SetVariableAssignHook(pset.vars, "QUIET", quiet_hook);
-	SetVariableAssignHook(pset.vars, "SINGLELINE", singleline_hook);
-	SetVariableAssignHook(pset.vars, "SINGLESTEP", singlestep_hook);
-	SetVariableAssignHook(pset.vars, "FETCH_COUNT", fetch_count_hook);
-	SetVariableAssignHook(pset.vars, "ECHO", echo_hook);
-	SetVariableAssignHook(pset.vars, "ECHO_HIDDEN", echo_hidden_hook);
-	SetVariableAssignHook(pset.vars, "ON_ERROR_ROLLBACK", on_error_rollback_hook);
-	SetVariableAssignHook(pset.vars, "COMP_KEYWORD_CASE", comp_keyword_case_hook);
-	SetVariableAssignHook(pset.vars, "HISTCONTROL", histcontrol_hook);
-	SetVariableAssignHook(pset.vars, "PROMPT1", prompt1_hook);
-	SetVariableAssignHook(pset.vars, "PROMPT2", prompt2_hook);
-	SetVariableAssignHook(pset.vars, "PROMPT3", prompt3_hook);
-	SetVariableAssignHook(pset.vars, "VERBOSITY", verbosity_hook);
-	SetVariableAssignHook(pset.vars, "SHOW_CONTEXT", show_context_hook);
+	SetVariableAssignHook(pset.vars, "AUTOCOMMIT", autocommit_hook, "on");
+	SetVariableAssignHook(pset.vars, "ON_ERROR_STOP", on_error_stop_hook, "off");
+	SetVariableAssignHook(pset.vars, "QUIET", quiet_hook, "off");
+	SetVariableAssignHook(pset.vars, "SINGLELINE", singleline_hook, "off");
+	SetVariableAssignHook(pset.vars, "SINGLESTEP", singlestep_hook, "off");
+	SetVariableAssignHook(pset.vars, "FETCH_COUNT", fetch_count_hook, "-1");
+	SetVariableAssignHook(pset.vars, "ECHO", echo_hook, "none");
+	SetVariableAssignHook(pset.vars, "ECHO_HIDDEN", echo_hidden_hook, "off");
+	SetVariableAssignHook(pset.vars, "ON_ERROR_ROLLBACK", on_error_rollback_hook, "off");
+	SetVariableAssignHook(pset.vars, "COMP_KEYWORD_CASE", comp_keyword_case_hook, "preserve-upper");
+	SetVariableAssignHook(pset.vars, "HISTCONTROL", histcontrol_hook, "none");
+	SetVariableAssignHook(pset.vars, "PROMPT1", prompt1_hook, DEFAULT_PROMPT1);
+	SetVariableAssignHook(pset.vars, "PROMPT2", prompt2_hook, DEFAULT_PROMPT2);
+	SetVariableAssignHook(pset.vars, "PROMPT3", prompt3_hook, DEFAULT_PROMPT3);
+	SetVariableAssignHook(pset.vars, "VERBOSITY", verbosity_hook, "default");
+	SetVariableAssignHook(pset.vars, "SHOW_CONTEXT", show_context_hook, "errors");
 }
diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
index 91e4ae8..2e5c3e0 100644
--- a/src/bin/psql/variables.c
+++ b/src/bin/psql/variables.c
@@ -288,9 +288,8 @@ SetVariable(VariableSpace space, const char *name, const char *value)
 /*
  * Attach an assign hook function to the named variable.
  *
- * If the variable doesn't already exist, create it with value NULL,
- * just so we have a place to store the hook function.  (Externally,
- * this isn't different from it not being defined.)
+ * If the variable doesn't already exist, create it with init_value as the
+ * content. init_value must not be NULL.
  *
  * The hook is immediately called on the variable's current value.  This is
  * meant to let it update any derived psql state.  If the hook doesn't like
@@ -299,7 +298,10 @@ SetVariable(VariableSpace space, const char *name, const char *value)
  * get called before any user-supplied value is assigned.
  */
 void
-SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook)
+SetVariableAssignHook(VariableSpace space,
+					  const char *name,
+					  VariableAssignHook hook,
+					  const char *init_value)
 {
 	struct _variable *current,
 			   *previous;
@@ -326,11 +328,11 @@ SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook
 	/* not present, make new entry */
 	current = pg_malloc(sizeof *current);
 	current->name = pg_strdup(name);
-	current->value = NULL;
+	current->value = pg_strdup(init_value);
 	current->assign_hook = hook;
 	current->next = NULL;
 	previous->next = current;
-	(void) (*hook) (NULL);
+	(void) (*hook) (current->value);
 }
 
 /*
diff --git a/src/bin/psql/variables.h b/src/bin/psql/variables.h
index 274b4af..94e7fb8 100644
--- a/src/bin/psql/variables.h
+++ b/src/bin/psql/variables.h
@@ -24,9 +24,9 @@
  * should print an error message with psql_error() to tell the user why.
  *
  * When a hook function is installed with SetVariableAssignHook(), it is
- * called with the variable's current value (or with NULL, if it wasn't set
- * yet).  But its return value is ignored in this case.  The hook should be
- * set before any possibly-invalid value can be assigned.
+ * called with the variable's initial value, but its return value is ignored
+ * in this case.
+ * The hook should be set before any possibly-invalid value can be assigned.
  */
 typedef bool (*VariableAssignHook) (const char *newval);
 
@@ -65,7 +65,10 @@ int GetVariableNum(VariableSpace space,
 void		PrintVariables(VariableSpace space);
 
 bool		SetVariable(VariableSpace space, const char *name, const char *value);
-void		SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook);
+void		SetVariableAssignHook(VariableSpace space,
+								  const char *name,
+								  VariableAssignHook hook,
+								  const char *init_value);
 bool		SetVariableBool(VariableSpace space, const char *name);
 bool		DeleteVariable(VariableSpace space, const char *name);