plug-ins: in file-gegl, use the accurate load/save GEGL operation…

… rather than generic "gegl:load" and "gegl:save".

In particular, it means using "gegl:rgbe-load|save" for RGBE images and
"gegl:exr-save" for EXR exporting.

Without this, we could encounter weird run cases where for instance, we
would detect a RGBE image through the file magic number in GIMP,
redirect the load to file-gegl, but "gegl:load" only relies on file
extension. So if the file extension was not ".hdr", "gegl:load" could
redirect to a different handler operation meant for another format,
hence break proper loading. If no extension was matched, it could even
redirect to a fallback handler, such as Image Magick.

This breaks loading or saving images which we would be otherwise able to
load/save. And it could also have some security implications. So let's
fix this by setting the accurate operations to use for each specific
file formats we want to support through the file-gegl plug-in.

plug-ins/common/file-gegl.c

@@ -46,10 +46,12 @@ struct _FileFormat
   const gchar *load_proc;
   const gchar *load_blurb;
   const gchar *load_help;
+  const gchar *load_op;
 
   const gchar *save_proc;
   const gchar *save_blurb;
   const gchar *save_help;
+  const gchar *save_op;
 };
 
 
@@ -91,8 +93,10 @@ static GimpValueArray * goat_save             (GimpProcedure        *procedure,
                                                gpointer              run_data);
 
 static GimpImage      * load_image            (GFile                *file,
+                                               const gchar          *gegl_op,
                                                GError              **error);
 static gboolean         save_image            (GFile                *file,
+                                               const gchar          *gegl_op,
                                                GimpImage            *image,
                                                GimpDrawable         *drawable,
                                                GError              **error);
@@ -113,11 +117,13 @@ static const FileFormat file_formats[] =
 
     "file-load-rgbe",
     "Load files in the RGBE file format",
-    "This procedure loads images in the RGBE format, using gegl:load",
+    "This procedure loads images in the RGBE format, using gegl:rgbe-load",
+    "gegl:rgbe-load",
 
     "file-save-rgbe",
     "Saves files in the RGBE file format",
-    "This procedure exports images in the RGBE format, using gegl:save"
+    "This procedure exports images in the RGBE format, using gegl:rgbe-save",
+    "gegl:rgbe-save",
   },
   {
     N_("OpenEXR image"),
@@ -126,11 +132,12 @@ static const FileFormat file_formats[] =
     "0,lelong,20000630",
 
     /* no EXR loading (implemented in native GIMP plug-in) */
-    NULL, NULL, NULL,
+    NULL, NULL, NULL, NULL,
 
     "file-exr-save",
     "Saves files in the OpenEXR file format",
-    "This procedure saves images in the OpenEXR format, using gegl:save"
+    "This procedure saves images in the OpenEXR format, using gegl:exr-save",
+    "gegl:exr-save"
   }
 };
 
@@ -234,14 +241,15 @@ goat_load (GimpProcedure        *procedure,
           const GimpValueArray *args,
           gpointer              run_data)
 {
-  GimpValueArray *return_vals;
-  GimpImage      *image;
-  GError         *error = NULL;
+  const FileFormat *format = run_data;
+  GimpValueArray   *return_vals;
+  GimpImage        *image;
+  GError           *error  = NULL;
 
   INIT_I18N ();
   gegl_init (NULL, NULL);
 
-  image = load_image (file, &error);
+  image = load_image (file, format->load_op, &error);
 
   if (! image)
     return gimp_procedure_new_return_values (procedure,
@@ -267,6 +275,7 @@ goat_save (GimpProcedure        *procedure,
            const GimpValueArray *args,
            gpointer              run_data)
 {
+  const FileFormat  *format = run_data;
   GimpPDBStatusType  status = GIMP_PDB_SUCCESS;
   GimpExportReturn   export = GIMP_EXPORT_CANCEL;
   GError            *error = NULL;
@@ -306,7 +315,7 @@ goat_save (GimpProcedure        *procedure,
                                                error);
     }
 
-  if (! save_image (file, image, drawables[0],
+  if (! save_image (file, format->save_op, image, drawables[0],
                     &error))
     {
       status = GIMP_PDB_EXECUTION_ERROR;
@@ -322,8 +331,9 @@ goat_save (GimpProcedure        *procedure,
 }
 
 static GimpImage *
-load_image (GFile   *file,
-            GError **error)
+load_image (GFile        *file,
+            const gchar  *gegl_op,
+            GError      **error)
 {
   GimpImage         *image;
   GimpLayer         *layer;
@@ -345,7 +355,7 @@ load_image (GFile   *file,
   graph = gegl_node_new ();
 
   source = gegl_node_new_child (graph,
-                                "operation", "gegl:load",
+                                "operation", gegl_op,
                                 "path",      g_file_peek_path (file),
                                 NULL);
   sink = gegl_node_new_child (graph,
@@ -478,6 +488,7 @@ load_image (GFile   *file,
 
 static gboolean
 save_image (GFile         *file,
+            const gchar   *gegl_op,
             GimpImage     *image,
             GimpDrawable  *drawable,
             GError       **error)
@@ -496,7 +507,7 @@ save_image (GFile         *file,
                                 "buffer",    src_buf,
                                 NULL);
   sink = gegl_node_new_child (graph,
-                              "operation", "gegl:save",
+                              "operation", gegl_op,
                               "path",      g_file_peek_path (file),
                               NULL);