From 16846473663b40e5517ad7230097b9bb38af99ed Mon Sep 17 00:00:00 2001
From: un-pogaz <46523284+un-pogaz@users.noreply.github.com>
Date: Fri, 29 Nov 2024 13:39:46 +0100
Subject: [PATCH] get safely template function doc

---
 src/calibre/gui2/dialogs/template_dialog.py | 40 ++++++++++++++++++---
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/src/calibre/gui2/dialogs/template_dialog.py b/src/calibre/gui2/dialogs/template_dialog.py
index eef0abd829..f171a50e54 100644
--- a/src/calibre/gui2/dialogs/template_dialog.py
+++ b/src/calibre/gui2/dialogs/template_dialog.py
@@ -62,6 +62,29 @@ from calibre.utils.localization import localize_user_manual_link, ngettext
 from calibre.utils.resources import get_path as P
 
 
+def safe_get_doc_html(ffml, func, fname, original_doc):
+    def build_error_msg(msg):
+        return '<span style="color:red"><strong>MalformedDoc:</strong> '+msg+'</span>'
+
+    # try with the original doc
+    try:
+        return ffml.document_to_html(original_doc, fname).strip()
+    except Exception as ex:
+        error_msg = build_error_msg(str(ex))
+
+    # try with english doc
+    doc = getattr(func, 'doc', '')
+    doc = getattr(doc, 'formatted_english', doc)
+    try:
+        rslt = ffml.document_to_html(doc, fname).strip()
+        return error_msg+'<br>'+ rslt
+    except Exception as ex:
+        error_msg = build_error_msg(str(ex))
+
+    # return raw doc
+    return error_msg+'<br>'+doc.strip()
+
+
 class DocViewer(Dialog):
 
     def __init__(self, ffml, builtins, function_type_string_method, parent=None):
@@ -140,9 +163,13 @@ class DocViewer(Dialog):
         return f'\n<h3>{name} ({self.function_type_string(name, longform=False)})</h3>\n'
 
     def get_doc(self, func):
-        doc = func.doc if hasattr(func, 'doc') else ''
+        doc = getattr(func, 'doc', '')
         return getattr(doc, 'formatted_english', doc) if self.english_cb.isChecked() else doc
 
+    def get_doc_html(self, func, fname):
+        doc = self.get_doc(func)
+        return safe_get_doc_html(self.ffml, func, fname, doc)
+
     def no_doc_string(self):
         if self.english_cb.isChecked():
             return 'No documentation provided'
@@ -161,7 +188,7 @@ class DocViewer(Dialog):
         else:
             self.last_function = fname
             self.set_html(self.header_line(fname) +
-                          self.ffml.document_to_html(self.get_doc(bif), fname))
+                          self.get_doc_html(bif, fname))
 
     def show_all_functions_button_clicked(self):
         self.add_to_back_stack()
@@ -179,7 +206,7 @@ class DocViewer(Dialog):
                 if not doc:
                     a(self.no_doc_string())
                 else:
-                    html = self.ffml.document_to_html(doc.strip(), name)
+                    html = self.get_doc_html(self.builtins[name], name)
                     name_pos = html.find(name + '(')
                     if name_pos < 0:
                         rest_of_doc = ' -- ' + html
@@ -1116,14 +1143,17 @@ def evaluate(book, context):
             return (_('Stored user defined Python template') if longform else _('Stored template'))
         return (_('Stored user defined GPM template') if longform else _('Stored template'))
 
+    def get_doc_html(self, func, fname):
+        doc = getattr(func, 'doc', '')
+        return safe_get_doc_html(self.ffml, func, fname, doc)
+
     def function_changed(self, toWhat):
         self.current_function_name = name = str(self.function.itemData(toWhat))
         self.source_code.clear()
         self.documentation.clear()
         self.func_type.clear()
         if name in self.all_functions:
-            doc = self.all_functions[name].doc.strip()
-            self.documentation.setHtml(self.ffml.document_to_html(doc, name))
+            self.documentation.setHtml(self.get_doc_html(self.all_functions[name], name))
             if self.doc_viewer is not None:
                 self.doc_viewer.show_function(name)
             if name in self.builtins and name in self.builtin_source_dict: