PyAPI: call 'sys.excepthook' for text editor exceptions

Resolves #115090, where exceptions from the text editor called
`sys.excepthook` in v3.6 but not in v4.0.

The error was caused by PyC_ExceptionBuffer calling PyErr_Display
instead of PyErr_Print.

While technically a regression in [0], the behavior in 3.6x wasn't
working properly either since a user-defined `sys.excepthook` could
prevent PyC_ExceptionBuffer from accessing the exception text.

Resolve with the following changes:

- BPy_errors_to_report has been updated not to print errors.
  Previously BPy_errors_to_report would *sometimes* print the error,
  which complicated situations where the caller wanted predictable
  behavior (always printing or never printing).

- `PyErr_Print()` must be used to display errors to the output,
  this will call `sys.excepthook` as it used to.

It's better not to rely on side effects of BPy_errors_to_report()
for error handling.

[0]: 6a0f98aeef

source/blender/freestyle/intern/system/PythonInterpreter.h

@@ -92,6 +92,7 @@ class PythonInterpreter : public Interpreter {
 
     if (!BPY_run_string_eval(_context, nullptr, str.c_str())) {
       BPy_errors_to_report(reports);
+      PyErr_Print();
       PyErr_Clear();
       cerr << "\nError executing Python script from PythonInterpreter::interpretString" << endl;
       cerr << "Name: " << name << endl;

source/blender/python/intern/bpy_capi_utils.cc

@@ -87,6 +87,17 @@ bool BPy_errors_to_report_ex(ReportList *reports,
     PyC_FileAndNum(&location_filepath, &location_line_number);
   }
 
+  /* Create a temporary report list so none of the reports are printed (only stored).
+   * In practically all cases printing should be handled by #PyErr_Print since this invokes
+   * `sys.excepthook` as expected. */
+  ReportList _reports_buf = {{0}};
+  ReportList *reports_orig = reports;
+  if ((reports->flag & RPT_PRINT_HANDLED_BY_OWNER) == 0) {
+    reports = &_reports_buf;
+    BKE_reports_init(reports, reports_orig->flag | RPT_PRINT_HANDLED_BY_OWNER);
+    reports->storelevel = reports_orig->storelevel;
+  }
+
   if (location_filepath) {
     BKE_reportf(reports,
                 RPT_ERROR,
@@ -103,6 +114,11 @@ bool BPy_errors_to_report_ex(ReportList *reports,
     BKE_reportf(reports, RPT_ERROR, "%s: %.*s", err_prefix, int(err_str_len), err_str);
   }
 
+  if (reports != reports_orig) {
+    BKE_reports_move_to_reports(reports_orig, reports);
+    BKE_reports_free(reports);
+  }
+
   /* Ensure this is _always_ printed to the output so developers don't miss exceptions. */
   Py_DECREF(err_str_py);
   return true;

source/blender/python/intern/bpy_capi_utils.h

@@ -32,16 +32,11 @@ bool BPy_errors_to_report_ex(struct ReportList *reports,
                              bool use_full,
                              bool use_location);
 /**
- * \param reports: When set, an error will be added to this report, when NULL, print the error.
+ * \param reports: Any errors will be added to the report list.
  *
- * \note Unless the caller handles printing the reports (or reports is NULL) it's best to ensure
- * the output is printed to the `stdout/stderr`:
- * \code{.cc}
- * BPy_errors_to_report(reports);
- * if (!BKE_reports_print_test(reports)) {
- *   BKE_reports_print(reports);
- * }
- * \endcode
+ * \note The reports are never printed to the `stdout/stderr`,
+ * so you may wish to call either `BKE_reports_print(reports)` or `PyErr_Print()` afterwards.
+ * Typically `PyErr_Print()` is preferable as `sys.excepthook` is called.
  *
  * \note The caller is responsible for clearing the error (see #PyErr_Clear).
  */

source/blender/python/intern/bpy_interface_run.cc

@@ -180,7 +180,9 @@ static bool python_script_exec(
   }
 
   if (!py_result) {
-    BPy_errors_to_report(reports);
+    if (reports) {
+      BPy_errors_to_report(reports);
+    }
     if (text) {
       if (do_jump) {
         /* ensure text is valid before use, the script may have freed itself */
@@ -190,6 +192,7 @@ static bool python_script_exec(
         }
       }
     }
+    PyErr_Print();
     PyErr_Clear();
   }
   else {
@@ -272,12 +275,9 @@ static bool bpy_run_string_impl(bContext *C,
     ReportList reports;
     BKE_reports_init(&reports, RPT_STORE);
     BPy_errors_to_report(&reports);
-    PyErr_Clear();
 
-    /* Ensure the reports are printed. */
-    if (!BKE_reports_print_test(&reports, RPT_ERROR)) {
-      BKE_reports_print(&reports, RPT_ERROR);
-    }
+    PyErr_Print();
+    PyErr_Clear();
 
     ReportList *wm_reports = CTX_wm_reports(C);
     if (wm_reports) {

source/blender/python/intern/bpy_rna.cc

@@ -8781,19 +8781,8 @@ static int bpy_class_call(bContext *C, PointerRNA *ptr, FunctionRNA *func, Param
       reports = CTX_wm_reports(C);
     }
 
-    /* Typically null reports are sent to the output,
-     * in this case however PyErr_Print is responsible for that,
-     * so only run this if reports are non-null. */
     if (reports) {
-      /* Create a temporary report list so none of the reports are printed (only stored).
-       * Only do this when reports is non-null because the error is printed to the `stderr`
-       * #PyErr_Print below. */
-      ReportList reports_temp = {{0}};
-      BKE_reports_init(&reports_temp, reports->flag | RPT_PRINT_HANDLED_BY_OWNER);
-      reports_temp.storelevel = reports->storelevel;
-      BPy_errors_to_report(&reports_temp);
-      BKE_reports_move_to_reports(reports, &reports_temp);
-      BKE_reports_free(&reports_temp);
+      BPy_errors_to_report(reports);
     }
 
     /* Also print in the console for Python. */