UI: errors in buttons now show in info report

Mistakes in button expressions were previously only printed to the console.

source/blender/python/generic/py_capi_utils.c

@@ -478,6 +478,34 @@ error_cleanup:
 }
 #endif
 
+PyObject *PyC_ExceptionBuffer_Simple(void)
+{
+	PyObject *string_io_buf;
+
+	PyObject *error_type, *error_value, *error_traceback;
+
+	if (!PyErr_Occurred())
+		return NULL;
+
+	PyErr_Fetch(&error_type, &error_value, &error_traceback);
+
+	if (error_value == NULL) {
+		return NULL;
+	}
+
+	string_io_buf = PyObject_Str(error_value);
+	/* Python does this too */
+	if (UNLIKELY(string_io_buf == NULL)) {
+		string_io_buf = PyUnicode_FromFormat(
+		        "<unprintable %s object>", Py_TYPE(error_value)->tp_name);
+	}
+
+	PyErr_Restore(error_type, error_value, error_traceback);
+
+	PyErr_Print();
+	PyErr_Clear();
+	return string_io_buf;
+}
 
 /* string conversion, escape non-unicode chars, coerce must be set to NULL */
 const char *PyC_UnicodeAsByte(PyObject *py_str, PyObject **coerce)

source/blender/python/generic/py_capi_utils.h

@@ -32,6 +32,7 @@ void			PyC_ObSpit(const char *name, PyObject *var);
 void			PyC_LineSpit(void);
 void			PyC_StackSpit(void);
 PyObject *		PyC_ExceptionBuffer(void);
+PyObject *		PyC_ExceptionBuffer_Simple(void);
 PyObject *		PyC_Object_GetAttrStringArgs(PyObject *o, Py_ssize_t n, ...);
 PyObject *		PyC_FrozenSetFromStrings(const char **strings);
 PyObject *		PyC_Err_Format_Prefix(PyObject *exception_type_prefix, const char *format, ...);

source/blender/python/intern/bpy_interface.c

@@ -595,7 +595,7 @@ int BPY_button_exec(bContext *C, const char *expr, double *value, const bool ver
 
 	if (error_ret) {
 		if (verbose) {
-			BPy_errors_to_report(CTX_wm_reports(C));
+			BPy_errors_to_report_ex(CTX_wm_reports(C), false, false);
 		}
 		else {
 			PyErr_Clear();

source/blender/python/intern/bpy_util.c

@@ -82,10 +82,9 @@ short BPy_reports_to_error(ReportList *reports, PyObject *exception, const bool
 }
 
 
-short BPy_errors_to_report(ReportList *reports)
+bool BPy_errors_to_report_ex(ReportList *reports, const bool use_full, const bool use_location)
 {
 	PyObject *pystring;
-	PyObject *pystring_format = NULL;  /* workaround, see below */
 	const char *cstring;
 
 	const char *filename;
@@ -101,31 +100,49 @@ short BPy_errors_to_report(ReportList *reports)
 		return 1;
 	}
 	
-	pystring = PyC_ExceptionBuffer();
+	if (use_full) {
+		pystring = PyC_ExceptionBuffer();
+	}
+	else {
+		pystring = PyC_ExceptionBuffer_Simple();
+	}
 	
 	if (pystring == NULL) {
 		BKE_report(reports, RPT_ERROR, "Unknown py-exception, could not convert");
 		return 0;
 	}
-	
-	PyC_FileAndNum(&filename, &lineno);
-	if (filename == NULL)
-		filename = "<unknown location>";
-	
+
 	cstring = _PyUnicode_AsString(pystring);
 
+	if (use_location) {
+		PyObject *pystring_format;  /* workaround, see below */
+
+		PyC_FileAndNum(&filename, &lineno);
+		if (filename == NULL) {
+			filename = "<unknown location>";
+		}
+
 #if 0 /* ARG!. workaround for a bug in blenders use of vsnprintf */
-	BKE_reportf(reports, RPT_ERROR, "%s\nlocation: %s:%d\n", cstring, filename, lineno);
+		BKE_reportf(reports, RPT_ERROR, "%s\nlocation: %s:%d\n", cstring, filename, lineno);
 #else
-	pystring_format = PyUnicode_FromFormat(TIP_("%s\nlocation: %s:%d\n"), cstring, filename, lineno);
-	cstring = _PyUnicode_AsString(pystring_format);
-	BKE_report(reports, RPT_ERROR, cstring);
+		pystring_format = PyUnicode_FromFormat(TIP_("%s\nlocation: %s:%d\n"), cstring, filename, lineno);
+		cstring = _PyUnicode_AsString(pystring_format);
+		BKE_report(reports, RPT_ERROR, cstring);
+		Py_DECREF(pystring_format);  /* workaround */
 #endif
+	}
+	else {
+		BKE_report(reports, RPT_ERROR, cstring);
+	}
 
 	/* not exactly needed. just for testing */
 	fprintf(stderr, TIP_("%s\nlocation: %s:%d\n"), cstring, filename, lineno);
 
 	Py_DECREF(pystring);
-	Py_DECREF(pystring_format);  /* workaround */
 	return 1;
 }
+
+bool BPy_errors_to_report(ReportList *reports)
+{
+	return BPy_errors_to_report_ex(reports, true, true);
+}

source/blender/python/intern/bpy_util.h

@@ -40,7 +40,8 @@ char *BPy_enum_as_string(struct EnumPropertyItem *item);
 
 /* error reporting */
 short BPy_reports_to_error(struct ReportList *reports, PyObject *exception, const bool clear);
-short BPy_errors_to_report(struct ReportList *reports);
+bool BPy_errors_to_report_ex(struct ReportList *reports, const bool use_full, const bool use_location);
+bool BPy_errors_to_report(struct ReportList *reports);
 
 /* TODO - find a better solution! */
 struct bContext *BPy_GetContext(void);