From 48efad6a2bd3b8adb34846fbffe81adbbc2f8a07 Mon Sep 17 00:00:00 2001
From: Geoff McLane <ubuntu@geoffair.info>
Date: Sun, 11 Oct 2020 17:51:06 +0200
Subject: [PATCH] Is. #839 - 2nd look - add new message for 'blank' title

This is a compromise -

   1. Keep insertion of a blank title tag, if none.
   2. Add new warn if title tag is blank, in html5

	modified:   include/tidyenum.h
	modified:   src/language_en.h
	modified:   src/message.c
	modified:   src/parser.c
---
 include/tidyenum.h |  3 ++-
 src/language_en.h  |  1 +
 src/message.c      |  2 ++
 src/parser.c       | 11 ++++++++++-
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/include/tidyenum.h b/include/tidyenum.h
index 3daee5b..76ae07d 100644
--- a/include/tidyenum.h
+++ b/include/tidyenum.h
@@ -282,7 +282,8 @@ extern "C" {
     FN(VENDOR_SPECIFIC_CHARS)         \
     FN(WHITE_IN_URI)                  \
     FN(XML_DECLARATION_DETECTED)      \
-    FN(XML_ID_SYNTAX)
+    FN(XML_ID_SYNTAX)                 \
+    FN(BLANK_TITLE_ELEMENT)
 
 
 /** These are report messages added by Tidy's accessibility module. 
diff --git a/src/language_en.h b/src/language_en.h
index 8d0eb7a..f93324e 100644
--- a/src/language_en.h
+++ b/src/language_en.h
@@ -2055,6 +2055,7 @@ static languageDefinition language_en = { whichPluralForm_en, {
     { WHITE_IN_URI,                 0,   "%s discarding whitespace in URI reference"                               },
     { XML_DECLARATION_DETECTED,     0,   "An XML declaration was detected. Did you mean to use input-xml?"         },
     { XML_ID_SYNTAX,                0,   "%s ID \"%s\" uses XML ID syntax"                                         },
+    { BLANK_TITLE_ELEMENT,          0,   "blank 'title' element"                                                   },
 
 
     /***************************************
diff --git a/src/message.c b/src/message.c
index ee2e6c6..de0124b 100644
--- a/src/message.c
+++ b/src/message.c
@@ -372,6 +372,7 @@ static struct _dispatchTable {
     { WHITE_IN_URI,                 TidyWarning,     formatAttributeReport   },
     { XML_DECLARATION_DETECTED,     TidyWarning,     formatStandard          },
     { XML_ID_SYNTAX,                TidyWarning,     formatAttributeReport   },
+    { BLANK_TITLE_ELEMENT,          TidyWarning,     formatStandard          },
 
     { APPLET_MISSING_ALT,                            TidyAccess, formatAccessReport },
     { AREA_MISSING_ALT,                              TidyAccess, formatAccessReport },
@@ -819,6 +820,7 @@ TidyMessageImpl *formatStandard(TidyDocImpl* doc, Node *element, Node *node, uin
         case NESTED_QUOTATION:
         case SUSPECTED_MISSING_QUOTE:
         case XML_DECLARATION_DETECTED:
+        case BLANK_TITLE_ELEMENT:
             return TY_(tidyMessageCreateWithNode)(doc, rpt, code, level );
 
         case ELEMENT_NOT_EMPTY:
diff --git a/src/parser.c b/src/parser.c
index 8569ed5..cda3200 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -4713,7 +4713,8 @@ void TY_(ParseDocument)(TidyDocImpl* doc)
         TY_(ParseHTML)(doc, html, IgnoreWhitespace);
     }
 
-    if (!TY_(FindTITLE)(doc))
+    node = TY_(FindTITLE)(doc);
+    if (!node)
     {
         Node* head = TY_(FindHEAD)(doc);
         /* #72, avoid MISSING_TITLE_ELEMENT if show-body-only (but allow InsertNodeAtEnd to avoid new warning) */
@@ -4723,6 +4724,14 @@ void TY_(ParseDocument)(TidyDocImpl* doc)
         }
         TY_(InsertNodeAtEnd)(head, TY_(InferredTag)(doc, TidyTag_TITLE));
     }
+    else if (!node->content && !showingBodyOnly(doc))
+    {
+        /* Is #839 - warn node is blank in HTML5 */
+        if (TY_(IsHTML5Mode)(doc))
+        {
+            TY_(Report)(doc, node, NULL, BLANK_TITLE_ELEMENT);
+        }
+    }
 
     AttributeChecks(doc, &doc->root);
     ReplaceObsoleteElements(doc, &doc->root);