[gimp] Issue #6033: fix calling gimp_pdb_run_procedure_argv() with no…

[Jehan <jehanp src gnome org>]

commit cbce7b3a982fa5fc1b2b5edc1a3ff358f030baad
Author: Lloyd Konneker <konnekerl gmail com>
Date:   Thu Apr 8 21:14:02 2021 +0000

    Issue #6033: fix calling gimp_pdb_run_procedure_argv() with no…
    
    … arguments and allow creating empty GimpValueArray.

 libgimp/gimppdb.c            | 12 +++++++-----
 libgimpbase/gimpvaluearray.c |  8 +++++---
 2 files changed, 12 insertions(+), 8 deletions(-)
---
diff --git a/libgimp/gimppdb.c b/libgimp/gimppdb.c
index 1b961b6d44..a8c64251c7 100644
--- a/libgimp/gimppdb.c
+++ b/libgimp/gimppdb.c
@@ -281,10 +281,10 @@ gimp_pdb_run_procedure_valist (GimpPDB     *pdb,
 
 /**
  * gimp_pdb_run_procedure_argv: (rename-to gimp_pdb_run_procedure)
- * @pdb:            the #GimpPDB object.
- * @procedure_name: the procedure registered name.
- * @arguments: (array length=n_arguments): the call arguments.
- * @n_arguments: the number of arguments.
+ * @pdb:                                              the #GimpPDB object.
+ * @procedure_name:                                   the registered name to call.
+ * @arguments: (array length=n_arguments) (nullable): the call arguments or %NULL.
+ * @n_arguments:                                      the number of arguments.
  *
  * Runs the procedure named @procedure_name with @arguments.
  *
@@ -303,7 +303,9 @@ gimp_pdb_run_procedure_argv (GimpPDB      *pdb,
 
   g_return_val_if_fail (GIMP_IS_PDB (pdb), NULL);
   g_return_val_if_fail (gimp_is_canonical_identifier (procedure_name), NULL);
-  g_return_val_if_fail (arguments != NULL, NULL);
+  /* Not require arguments != NULL.
+   * gimp_value_array_new_from_values(NULL, 0) will return empty GValueArray.
+   */
 
   args = gimp_value_array_new_from_values (arguments, n_arguments);
   return_values = gimp_pdb_run_procedure_array (pdb, procedure_name, args);
diff --git a/libgimpbase/gimpvaluearray.c b/libgimpbase/gimpvaluearray.c
index 6923e47647..d0bbc867c6 100644
--- a/libgimpbase/gimpvaluearray.c
+++ b/libgimpbase/gimpvaluearray.c
@@ -256,7 +256,7 @@ gimp_value_array_new_from_types_valist (gchar   **error_msg,
  * @n_values: the number of value elements
  *
  * Allocate and initialize a new #GimpValueArray, and fill it with
- * the given #GValues.
+ * the given #GValues.  When no #GValues are given, returns empty #GimpValueArray.
  *
  * Returns: a newly allocated #GimpValueArray.
  *
@@ -269,8 +269,10 @@ gimp_value_array_new_from_values (const GValue *values,
   GimpValueArray *value_array;
   gint i;
 
-  g_return_val_if_fail (values != NULL, NULL);
-  g_return_val_if_fail (n_values > 0, NULL);
+  /* n_values is zero if and only if values is NULL. */
+  g_return_val_if_fail ((n_values == 0  && values == NULL) ||
+                        (n_values > 0 && values != NULL),
+                        NULL);
 
   value_array = gimp_value_array_new (n_values);