quite a few python panels (10 or so) had names longer then the PanelType allowed,

for panels it would fail silently but for menu's it meant further references would give errors.

increase the registered class name from 32 to 64 and raise an error if the limit reached.

source/blender/blenkernel/BKE_screen.h

@@ -55,7 +55,7 @@ struct uiMenuItem;
    ED_spacetypes_init() in editors/area/spacetypes.c   */
 /* an editor in Blender is a combined ScrArea + SpaceType + SpaceData */
 
-#define BKE_ST_MAXNAME	32
+#define BKE_ST_MAXNAME	64
 
 typedef struct SpaceType {
 	struct SpaceType *next, *prev;

source/blender/makesrna/intern/rna_ID.c

@@ -205,6 +205,15 @@ StructRNA *rna_IDPropertyGroup_register(const bContext *C, ReportList *reports,
 	if(validate(&dummyptr, data, NULL) != 0)
 		return NULL;
 
+	/* note: it looks like there is no length limit on the srna id since its
+	 * just a char pointer, but take care here, also be careful that python
+	 * owns the string pointer which it could potentually free while blender
+	 * is running. */
+	if(strlen(identifier) >= sizeof(((IDProperty *)NULL)->name)) {
+		BKE_reportf(reports, RPT_ERROR, "registering id property class: '%s' is too long, maximum length is %d.", identifier, sizeof(((IDProperty *)NULL)->name));
+		return NULL;
+	}
+
 	return RNA_def_struct(&BLENDER_RNA, identifier, "IDPropertyGroup");  // XXX
 }
 

source/blender/makesrna/intern/rna_render.c

@@ -126,6 +126,11 @@ static StructRNA *rna_RenderEngine_register(const bContext *C, ReportList *repor
 	if(validate(&dummyptr, data, have_function) != 0)
 		return NULL;
 
+	if(strlen(identifier) >= sizeof(dummyet.idname)) {
+		BKE_reportf(reports, RPT_ERROR, "registering render engine class: '%s' is too long, maximum length is %d.", identifier, sizeof(dummyet.idname));
+		return NULL;
+	}
+
 	/* check if we have registered this engine type before, and remove it */
 	for(et=R_engines.first; et; et=et->next) {
 		if(strcmp(et->idname, dummyet.idname) == 0) {

source/blender/makesrna/intern/rna_ui.c

@@ -164,6 +164,11 @@ static StructRNA *rna_Panel_register(const bContext *C, ReportList *reports, voi
 	if(validate(&dummyptr, data, have_function) != 0)
 		return NULL;
 		
+	if(strlen(identifier) >= sizeof(dummypt.idname)) {
+		BKE_reportf(reports, RPT_ERROR, "registering panel class: '%s' is too long, maximum length is %d.", identifier, sizeof(dummypt.idname));
+		return NULL;
+	}
+	
 	if(!(art=region_type_find(reports, dummypt.space_type, dummypt.region_type)))
 		return NULL;
 
@@ -261,6 +266,11 @@ static StructRNA *rna_Header_register(const bContext *C, ReportList *reports, vo
 	if(validate(&dummyhtr, data, have_function) != 0)
 		return NULL;
 
+	if(strlen(identifier) >= sizeof(dummyht.idname)) {
+		BKE_reportf(reports, RPT_ERROR, "registering header class: '%s' is too long, maximum length is %d.", identifier, sizeof(dummyht.idname));
+		return NULL;
+	}
+
 	if(!(art=region_type_find(reports, dummyht.space_type, RGN_TYPE_HEADER)))
 		return NULL;
 
@@ -374,6 +384,11 @@ static StructRNA *rna_Menu_register(const bContext *C, ReportList *reports, void
 	if(validate(&dummymtr, data, have_function) != 0)
 		return NULL;
 	
+	if(strlen(identifier) >= sizeof(dummymt.idname)) {
+		BKE_reportf(reports, RPT_ERROR, "registering menu class: '%s' is too long, maximum length is %d.", identifier, sizeof(dummymt.idname));
+		return NULL;
+	}
+
 	/* check if we have registered this menu type before, and remove it */
 	mt= WM_menutype_find(dummymt.idname, TRUE);
 	if(mt && mt->ext.srna)

source/blender/render/extern/include/RE_pipeline.h

@@ -253,8 +253,8 @@ typedef struct RenderEngineType {
 	struct RenderEngineType *next, *prev;
 
 	/* type info */
-	char idname[32];
+	char idname[64]; // best keep the same size as BKE_ST_MAXNAME
-	char name[32];
+	char name[64];
 	int flag;
 
 	void (*render)(struct RenderEngine *engine, struct Scene *scene);