[gimp] libgimp, plug-ins: remove n_procedures from (init|query)_procedures().

[Jehan <jehanp src gnome org>]

commit bc7b3588025dec019e91c6e1944c439e6b3a0279
Author: Jehan <jehan girinstud io>
Date:   Fri Aug 2 13:36:11 2019 +0200

    libgimp, plug-ins: remove n_procedures from (init|query)_procedures().
    
    The way currently implemented plug-ins are, they are already
    NULL-terminating the returned arrays. Since a procedure name cannot be
    NULL itself by definition, defining the array length by a terminal NULL
    is enough. There is no need to also add a n_procedures parameters which
    is just one more possible bug source, even more as we were already
    expecting the NULL termination by using g_strfreev() to free the memory.
    
    Anyway a length parameter does not bring any advantage since a plug-in
    can still "lie" about its array size (just as it can forget to
    NULL-terminate it) and when this happens, the plug-in will segfault.
    That's it, it's just a plug-in programming error.
    
    Last but not least, some binding seem to have issues with returned array
    setting an (out) parameter as the length. In pygobject at least, the
    length parameter doesn't disappear and we end up with this ugly
    signature:
    
    > In [3]: Gimp.PlugIn.do_query_procedures.__doc__
    > Out[3]: 'query_procedures(self) -> list, n_procedures:int'
    
    See bug report pygobject#352.
    To avoid this, we should either set both the array and the length as
    (out) parameters or just set the returned array as NULL-terminated
    (which is the solution I chose).

 libgimp/gimpplugin-private.c           | 15 ++++++---------
 libgimp/gimpplugin.h                   | 12 ++++--------
 plug-ins/common/goat-exercise.c        |  8 ++------
 plug-ins/help/help.c                   |  8 ++------
 plug-ins/python/palette-to-gradient.py |  3 +--
 5 files changed, 15 insertions(+), 31 deletions(-)
---
diff --git a/libgimp/gimpplugin-private.c b/libgimp/gimpplugin-private.c
index 76c4e2b144..83c631e578 100644
--- a/libgimp/gimpplugin-private.c
+++ b/libgimp/gimpplugin-private.c
@@ -94,22 +94,19 @@ gimp_plug_in_register (GimpPlugIn *plug_in,
                        gboolean    init)
 {
   gchar **procedures;
-  gint    n_procedures;
-  gint    i;
+  gchar **name;
   GList  *list;
 
   if (init)
-    procedures = GIMP_PLUG_IN_GET_CLASS (plug_in)->init_procedures (plug_in,
-                                                                    &n_procedures);
+    procedures = GIMP_PLUG_IN_GET_CLASS (plug_in)->init_procedures (plug_in);
   else
-    procedures = GIMP_PLUG_IN_GET_CLASS (plug_in)->query_procedures (plug_in,
-                                                                     &n_procedures);
+    procedures = GIMP_PLUG_IN_GET_CLASS (plug_in)->query_procedures (plug_in);
 
-  for (i = 0; i < n_procedures; i++)
+  for (name = procedures; *name; name++)
     {
       GimpProcedure *procedure;
 
-      procedure = gimp_plug_in_create_procedure (plug_in, procedures[i]);
+      procedure = gimp_plug_in_create_procedure (plug_in, *name);
       if (procedure)
         {
           _gimp_procedure_register (procedure);
@@ -118,7 +115,7 @@ gimp_plug_in_register (GimpPlugIn *plug_in,
       else
         {
           g_warning ("Plug-in failed to create procedure '%s'\n",
-                     procedures[i]);
+                     *name);
         }
     }
   g_clear_pointer (&procedures, g_strfreev);
diff --git a/libgimp/gimpplugin.h b/libgimp/gimpplugin.h
index a82bda55c9..5f952df214 100644
--- a/libgimp/gimpplugin.h
+++ b/libgimp/gimpplugin.h
@@ -56,7 +56,6 @@ struct _GimpPlugInClass
   /**
    * GimpPlugInClass::query_procedures:
    * @plug_in: a #GimpPlugIn.
-   * @n_procedures: (out): number of procedures.
    *
    * This method can be overridden by all plug-ins to return a newly
    * allocated array of allocated strings naming the procedures
@@ -66,16 +65,14 @@ struct _GimpPlugInClass
    *
    * See documentation of init_procedures() for differences.
    *
-   * Returns: (array length=n_procedures) (transfer full):
+   * Returns: (array zero-terminated=1) (transfer full):
    *          the names of the procedures registered by @plug_in.
    */
-  gchar         ** (* query_procedures) (GimpPlugIn  *plug_in,
-                                         gint        *n_procedures);
+  gchar         ** (* query_procedures) (GimpPlugIn  *plug_in);
 
   /**
    * GimpPlugInClass::init_procedures:
    * @plug_in: a #GimpPlugIn.
-   * @n_procedures: (out): number of procedures.
    *
    * This method can be overridden by all plug-ins to return a newly
    * allocated array of allocated strings naming procedures registered
@@ -92,11 +89,10 @@ struct _GimpPlugInClass
    * Most of the time, you only want to override query_procedures() and
    * leave init_procedures() untouched.
    *
-   * Returns: (array length=n_procedures) (transfer full):
+   * Returns: (array zero-terminated=1) (transfer full):
    *          the names of the procedures registered by @plug_in.
    */
-  gchar         ** (* init_procedures)  (GimpPlugIn  *plug_in,
-                                         gint        *n_procedures);
+  gchar         ** (* init_procedures)  (GimpPlugIn  *plug_in);
   /**
    * GimpPlugInClass::create_procedure:
    * @plug_in: a #GimpPlugIn.
diff --git a/plug-ins/common/goat-exercise.c b/plug-ins/common/goat-exercise.c
index e78e782bde..986dd2ed54 100644
--- a/plug-ins/common/goat-exercise.c
+++ b/plug-ins/common/goat-exercise.c
@@ -52,8 +52,7 @@ struct _GoatClass
 
 GType                   goat_get_type         (void) G_GNUC_CONST;
 
-static gchar         ** goat_query_procedures (GimpPlugIn           *plug_in,
-                                               gint                 *n_procedures);
+static gchar         ** goat_query_procedures (GimpPlugIn           *plug_in);
 static GimpProcedure  * goat_create_procedure (GimpPlugIn           *plug_in,
                                                const gchar          *name);
 
@@ -82,15 +81,12 @@ goat_init (Goat *goat)
 }
 
 static gchar **
-goat_query_procedures (GimpPlugIn *plug_in,
-                       gint       *n_procedures)
+goat_query_procedures (GimpPlugIn *plug_in)
 {
   gchar **procedures = g_new0 (gchar *, 2);
 
   procedures[0] = g_strdup (PLUG_IN_PROC);
 
-  *n_procedures = 1;
-
   return procedures;
 }
 
diff --git a/plug-ins/help/help.c b/plug-ins/help/help.c
index 0f557669fc..ffa1f5b365 100644
--- a/plug-ins/help/help.c
+++ b/plug-ins/help/help.c
@@ -70,8 +70,7 @@ typedef struct
 
 GType                   help_get_type          (void) G_GNUC_CONST;
 
-static gchar         ** help_query_procedures  (GimpPlugIn           *plug_in,
-                                                gint                 *n_procedures);
+static gchar         ** help_query_procedures  (GimpPlugIn           *plug_in);
 static GimpProcedure  * help_create_procedure  (GimpPlugIn           *plug_in,
                                                 const gchar          *name);
 
@@ -114,15 +113,12 @@ help_init (Help *help)
 }
 
 static gchar **
-help_query_procedures (GimpPlugIn *plug_in,
-                       gint       *n_procedures)
+help_query_procedures (GimpPlugIn *plug_in)
 {
   gchar **procedures = g_new0 (gchar *, 2);
 
   procedures[0] = g_strdup (GIMP_HELP_EXT_PROC);
 
-  *n_procedures = 1;
-
   return procedures;
 }
 
diff --git a/plug-ins/python/palette-to-gradient.py b/plug-ins/python/palette-to-gradient.py
index 9d0bc59306..e161dbb050 100644
--- a/plug-ins/python/palette-to-gradient.py
+++ b/plug-ins/python/palette-to-gradient.py
@@ -79,9 +79,8 @@ class PaletteToGradient (Gimp.PlugIn):
         self.set_translation_domain ("gimp30-python",
                                      Gio.file_new_for_path(Gimp.locale_directory()))
 
-        # XXX See pygobject#352 for the weird return value.
         return ['python-fu-palette-to-gradient',
-                'python-fu-palette-to-gradient-repeating'], 2
+                'python-fu-palette-to-gradient-repeating']
 
     def do_create_procedure(self, name):
         procedure = Gimp.Procedure.new(self, name,