[fix] revision of utils.HTMLTextExtractor (#5125)

Related:

- https://github.com/searxng/searxng/pull/5073#issuecomment-3196282632

searx/utils.py

@@ -74,11 +74,7 @@ def gen_useragent(os_string: Optional[str] = None) -> str:
     return USER_AGENTS['ua'].format(os=os_string or choice(USER_AGENTS['os']), version=choice(USER_AGENTS['versions']))
 
 
-class _HTMLTextExtractorException(Exception):
-    """Internal exception raised when the HTML is invalid"""
-
-
-class _HTMLTextExtractor(HTMLParser):
+class HTMLTextExtractor(HTMLParser):
     """Internal class to extract text from HTML"""
 
     def __init__(self):
@@ -96,7 +92,8 @@ class _HTMLTextExtractor(HTMLParser):
             return
 
         if tag != self.tags[-1]:
-            raise _HTMLTextExtractorException()
+            self.result.append(f"</{tag}>")
+            return
 
         self.tags.pop()
 
@@ -149,23 +146,28 @@ def html_to_text(html_str: str) -> str:
         >>> html_to_text('<style>.span { color: red; }</style><span>Example</span>')
         'Example'
 
-        >>> html_to_text(r'regexp: (?<![a-zA-Z]')
+        >>> html_to_text(r'regexp: (?&lt;![a-zA-Z]')
         'regexp: (?<![a-zA-Z]'
+
+        >>> html_to_text(r'<p><b>Lorem ipsum </i>dolor sit amet</p>')
+        'Lorem ipsum </i>dolor sit amet</p>'
+
+        >>> html_to_text(r'&#x3e &#x3c &#97')
+        '> < a'
+
     """
     if not html_str:
         return ""
     html_str = html_str.replace('\n', ' ').replace('\r', ' ')
     html_str = ' '.join(html_str.split())
-    s = _HTMLTextExtractor()
+    s = HTMLTextExtractor()
     try:
         s.feed(html_str)
         s.close()
     except AssertionError:
-        s = _HTMLTextExtractor()
+        s = HTMLTextExtractor()
         s.feed(escape(html_str, quote=True))
         s.close()
-    except _HTMLTextExtractorException:
-        logger.debug("HTMLTextExtractor: invalid HTML\n%s", html_str)
     return s.get_text()