Lynx patch to add H1-H6 headings link list to List Page

lynx-headingslist.patch

diff --git a/src/GridText.c b/src/GridText.c
index d9a1665..b3c41e0 100644
--- a/src/GridText.c
+++ b/src/GridText.c
@@ -6257,6 +6257,34 @@ HTChildAnchor *HText_childNextNumber(int number, void **prev)
     return a->anchor;
 }
 
+#ifdef EXP_HEADINGLIST
+/* returns not only HREF anchor which has number
+ * but also NAME or ID attribute anchor */
+HTChildAnchor *HText_childNext(void **prev)
+{
+    TextAnchor *a = (TextAnchor *) *prev;
+
+    if (!HTMainText)
+	return (HTChildAnchor *) 0;	/* Fail */
+    if (!a)
+	a = HTMainText->first_anchor;
+    else
+	a = a->next;
+
+    for (; a != 0; a = a->next) {
+	if (a->number > 0) /* HREF anchor */
+	    break;
+	if (a->anchor && a->anchor->tag) /* NAME or ID attribute anchor */
+	    break;
+    }
+
+    if (!a)
+	return (HTChildAnchor *) 0;	/* Fail */
+    *prev = (void *) a;
+    return a->anchor;
+}
+#endif /* EXP_HEADINGLIST */
+
 /*
  * For the -unique-urls option, find the anchor-number of the first occurrence
  * of a given address.
@@ -9573,6 +9601,49 @@ const char *HText_HiddenLinkAt(HText *text, int number)
     return (href);
 }
 
+#ifdef EXP_HEADINGLIST
+int HText_PoundCount(BOOL onlyLynxHeading)
+{
+    int count = 0;
+    TextAnchor *a;
+
+    for (a = HTMainText->first_anchor; a != 0; a = a->next) {
+	if (a->anchor && non_empty(a->anchor->tag)) {
+	    if (!onlyLynxHeading)
+		count++;
+	    else if (isLYNXHEADING(a->anchor->tag))
+		count++;
+	}
+    }
+    return (count);
+}
+
+HTChildAnchor *HText_PoundNext(BOOL onlyLynxHeading, int *linenum, void **prev)
+{
+    TextAnchor *a = (TextAnchor *) *prev;
+    *linenum = 0;
+
+    if (!HTMainText)
+	return (HTChildAnchor *) 0;	/* Fail */
+    if (!a)
+	a = HTMainText->first_anchor;
+
+    for (; a != 0; a = a->next)
+	if (a->anchor && non_empty(a->anchor->tag)) {
+	    if (!onlyLynxHeading)
+		break;
+	    else if (isLYNXHEADING(a->anchor->tag))
+		break;
+	}
+
+    if (!a)
+	return (HTChildAnchor *) 0;	/* Fail */
+    *prev = (void *) a->next;
+    *linenum = a->line_num;
+    return a->anchor;
+}
+#endif /* EXP_HEADINGLIST */
+
 /*
  * Form methods
  * These routines are used to build forms consisting
diff --git a/src/GridText.h b/src/GridText.h
index 40b17b1..c53925f 100644
--- a/src/GridText.h
+++ b/src/GridText.h
@@ -183,6 +183,11 @@ US-ASCII control characters <32 which are not defined in Unicode standard
     extern void HText_setNodeAnchorBookmark(const char *bookmark);
     extern void HText_setTabID(HText *text, const char *name);
     extern void *HText_pool_calloc(HText *text, unsigned size);
+#ifdef EXP_HEADINGLIST
+    extern HTChildAnchor *HText_childNext(void **prev);
+    extern int HText_PoundCount(BOOL onlyLynxHeading);
+    extern HTChildAnchor *HText_PoundNext(BOOL onlyLynxHeading, int *linenum, void **prev);
+#endif
 
 /* "simple table" stuff */
     extern BOOLEAN HText_endStblTABLE(HText *);
diff --git a/src/HTML.c b/src/HTML.c
index 3ab8373..04c9b8a 100644
--- a/src/HTML.c
+++ b/src/HTML.c
@@ -1835,6 +1839,9 @@ static int HTML_start_element(HTStructured * me, int element_number,
 		me->inP = FALSE;
 	    }
 	    CHECK_ID(HTML_H_ID);
+#ifdef EXP_HEADINGLIST
+	    LYAddHeadingID(me, ElementNumber);
+#endif
 	    break;
 	}
 
@@ -1862,6 +1869,9 @@ static int HTML_start_element(HTStructured * me, int element_number,
 	}
 	UPDATE_STYLE;
 	CHECK_ID(HTML_H_ID);
+#ifdef EXP_HEADINGLIST
+	LYAddHeadingID(me, ElementNumber);
+#endif
 
 	if ((bold_headers == TRUE ||
 	     (ElementNumber == HTML_H1 && bold_H1 == TRUE)) &&
@@ -7583,6 +7593,9 @@ HTStructured *HTML_new(HTParentAnchor *anchor,
     me->CurrentANum = 0;
     me->base_href = NULL;
     me->map_address = NULL;
+#ifdef EXP_HEADINGLIST
+    me->nextHeadingSeqNum = 0;
+#endif
 
     HTChunkInit(&me->title, 128);
 
diff --git a/src/HTML.h b/src/HTML.h
index 9f5d1d5..0fcd1c8 100644
--- a/src/HTML.h
+++ b/src/HTML.h
@@ -75,6 +75,9 @@ extern "C" {
 	int CurrentANum;	/* current HTML_A number */
 	char *base_href;	/* current HTML_BASE href */
 	char *map_address;	/* current HTML_MAP address */
+#ifdef EXP_HEADINGLIST
+	int nextHeadingSeqNum;	/* next HTML_H# sequence number */
+#endif
 
 	HTChunk title;		/* Grow by 128 */
 	HTChunk object;		/* Grow by 128 */
diff --git a/src/LYCharUtils.c b/src/LYCharUtils.c
index 03b2e81..8461ff7 100644
--- a/src/LYCharUtils.c
+++ b/src/LYCharUtils.c
@@ -3135,6 +3135,32 @@ void LYHandleID(HTStructured * me, const char *id)
     }
 }
 
+#ifdef EXP_HEADINGLIST
+void LYAddHeadingID(HTStructured * me, int element_number)
+{
+    HTChildAnchor *ID_A = NULL;
+    char *id = 0;
+
+    if (!(me && me->text))
+	return;
+
+    HTSprintf0(&id, "%s%d_H%d", STR_LYNXHEADING, me->nextHeadingSeqNum,
+	element_number - HTML_H1 + 1);
+    me->nextHeadingSeqNum++;
+
+    if ((ID_A = HTAnchor_findChildAndLink
+	 (
+	     me->node_anchor,	/* Parent */
+	     id,		/* Tag */
+	     NULL,		/* Address */
+	     (HTLinkType *) 0)) != NULL) {	/* Type */
+	HText_beginAnchor(me->text, me->inUnderline, ID_A);
+	HText_endAnchor(me->text, 0);
+    }
+    FREE(id);
+}
+#endif /* EXP_HEADINGLIST */
+
 /*
  *  This function checks whether we want to override
  *  the current default alignment for paragraphs and
diff --git a/src/LYCharUtils.h b/src/LYCharUtils.h
index 2b9ca88..8ffc4f8 100644
--- a/src/LYCharUtils.h
+++ b/src/LYCharUtils.h
@@ -92,6 +92,9 @@ extern "C" {
 			     STRING2PTR value,
 			     int attribute);
     extern void LYHandleID(HTStructured * me, const char *id);
+#ifdef EXP_HEADINGLIST
+    extern void LYAddHeadingID(HTStructured * me, int element_number);
+#endif
     extern BOOLEAN LYoverride_default_alignment(HTStructured * me);
     extern void LYEnsureDoubleSpace(HTStructured * me);
     extern void LYEnsureSingleSpace(HTStructured * me);
diff --git a/src/LYList.c b/src/LYList.c
index 989b6a3..dc0a1bf 100644
--- a/src/LYList.c
+++ b/src/LYList.c
@@ -44,6 +44,9 @@ int showlist(DocInfo *newdoc, int titles)
 {
     int cnt;
     int refs, hidden_links;
+#ifdef EXP_HEADINGLIST
+    int pounds;
+#endif
     int result;
     static char tempfile[LY_MAXPATH];
     static BOOLEAN last_titles = TRUE;
@@ -56,12 +59,23 @@ int showlist(DocInfo *newdoc, int titles)
 
     refs = HText_sourceAnchors(HTMainText);
     hidden_links = HText_HiddenLinkCount(HTMainText);
+#ifdef EXP_HEADINGLIST
+    pounds = HText_PoundCount(TRUE);
+#endif
     if (refs <= 0 && hidden_links > 0 &&
-	LYHiddenLinks != HIDDENLINKS_SEPARATE) {
+	LYHiddenLinks != HIDDENLINKS_SEPARATE
+#ifdef EXP_HEADINGLIST
+	&& pounds <= 0
+#endif
+	) {
 	HTUserMsg(NO_VISIBLE_REFS_FROM_DOC);
 	return (-1);
     }
-    if (refs <= 0 && hidden_links <= 0) {
+    if (refs <= 0 && hidden_links <= 0
+#ifdef EXP_HEADINGLIST
+	&& pounds <= 0
+#endif
+	) {
 	HTUserMsg(NO_REFS_FROM_DOC);
 	return (-1);
     }
@@ -91,10 +105,18 @@ int showlist(DocInfo *newdoc, int titles)
 	     ? Address
 	     : gettext("this document:")));
     FREE(Address);
+#ifdef EXP_HEADINGLIST
+    if (pounds)
+	fprintf(fp0, "<a href='#headings'>#%s</a><p>\n", gettext("H1-H6"));
+#endif
     if (refs > 0) {
 	fprintf(fp0, "<%s compact>\n", ((keypad_mode == NUMBERS_AS_ARROWS) ?
 					"ol" : "ul"));
-	if (hidden_links > 0)
+	if (hidden_links > 0
+#ifdef EXP_HEADINGLIST
+	    || pounds > 0
+#endif
+	    )
 	    fprintf(fp0, "<lh><em>%s</em>\n", gettext("Visible links:"));
     }
     if (hidden_links > 0) {
@@ -103,8 +125,13 @@ int showlist(DocInfo *newdoc, int titles)
     }
     helper = NULL;		/* init */
     result = 1;
+#ifdef EXP_HEADINGLIST
+    for (cnt = 0; cnt < refs; ) {
+	HTChildAnchor *child = HText_childNext(&helper);
+#else
     for (cnt = 1; cnt <= refs; cnt++) {
 	HTChildAnchor *child = HText_childNextNumber(cnt, &helper);
+#endif
 	int value = HText_findAnchorNumber(helper);
 	HTAnchor *dest_intl = NULL;
 	HTAnchor *dest;
@@ -112,6 +139,24 @@ int showlist(DocInfo *newdoc, int titles)
 	char *address;
 	const char *title;
 
+#ifdef EXP_HEADINGLIST
+	if (child != 0 && value == 0) {
+	    if (isLYNXHEADING(child->tag)) {
+		Address = HTAnchor_address((HTAnchor *) child);
+		LYEntify(&Address, TRUE);
+		fprintf(fp0, "<%s compact>",
+			((keypad_mode == NUMBERS_AS_ARROWS) ? "ol" : "ul"));
+		fprintf(fp0,
+			"<li><a href=\"%s\" TYPE=\"internal link\">#%s</a>",
+			Address, child->tag);
+		fprintf(fp0, "</%s>\n",
+			((keypad_mode == NUMBERS_AS_ARROWS) ? "ol" : "ul"));
+		FREE(Address);
+	    }
+	    continue;
+	}
+	++cnt;
+#endif
 	if (child == 0) {
 	    /*
 	     * child should not be 0 unless form field numbering is on and cnt
@@ -214,6 +259,30 @@ int showlist(DocInfo *newdoc, int titles)
 	FREE(Address);
     }
 
+#ifdef EXP_HEADINGLIST
+    if (pounds > 0) {
+	if (refs > 0 || hidden_links > 0)
+	    fprintf(fp0, "\n</%s>\n\n<p>\n",
+		    ((keypad_mode == NUMBERS_AS_ARROWS) ?
+		     "ol" : "ul"));
+	fprintf(fp0, "<%s compact>\n", ((keypad_mode == NUMBERS_AS_ARROWS) ?
+					"ol continue" : "ul"));
+	fprintf(fp0, "<lh id=\"headings\"><em>%s</em>\n", gettext("H1-H6:"));
+    }
+
+    helper = NULL;		/* init */
+    for (cnt = 0; cnt < pounds; cnt++) {
+	int linenum = 0;
+	HTChildAnchor *child = HText_PoundNext(TRUE, &linenum, &helper);
+	Address = HTAnchor_address((HTAnchor *) child);
+	LYEntify(&Address, TRUE);
+	fprintf(fp0,
+		"<li><a href=\"%s\" TYPE=\"internal link\">#%s</a> (line %d)\n",
+		Address, child->tag, linenum);
+	FREE(Address);
+    }
+#endif /* EXP_HEADINGLIST */
+
     fprintf(fp0, "\n</%s>\n", ((keypad_mode == NUMBERS_AS_ARROWS) ?
 			       "ol" : "ul"));
     EndInternalPage(fp0);
diff --git a/src/LYUtils.h b/src/LYUtils.h
index d15a816..8ae3749 100644
--- a/src/LYUtils.h
+++ b/src/LYUtils.h
@@ -532,6 +532,13 @@ extern "C" {
                              !strncasecomp(addr, STR_LYNXPROG, LEN_LYNXPROG))
 
 #define LYNXOPTIONS_PAGE(s)  STR_LYNXOPTIONS s
+
+/* internal fragment identifiers after '#' */
+#ifdef EXP_HEADINGLIST
+#define STR_LYNXHEADING      ":~:LYNXHEADING_"
+#define LEN_LYNXHEADING      15
+#define isLYNXHEADING(tag)   !strncasecomp(tag, STR_LYNXHEADING, LEN_LYNXHEADING)
+#endif
 /*
  *  For change_sug_filename().
  */
diff --git a/userdefs.h b/userdefs.h
index 4fe7937..b3d2fcb 100644
--- a/userdefs.h
+++ b/userdefs.h
@@ -1684,6 +1684,11 @@
  */
 #define EXP_PPRE
 
+/**************************
+ * Add H1-H6 heading links to ADDRLIST and LIST pages
+ */
+#define EXP_HEADINGLIST
+
 /****************************************************************
  *  Section 4.  Things you MUST check only if you plan to use Lynx
  *              in an anonymous account (allow public access to Lynx).