add the new runtime flag ALT_AS_TITLE; if an image has no title, use the alt text as the title

flags.c

@@ -37,6 +37,7 @@ static struct flagnames flagnames[] = {
     { MKD_URLENCODEDANCHOR, "URLENCODEDANCHOR" },
     { MKD_LATEX,          "LATEX" },
     { MKD_EXPLICITLIST,   "EXPLICITLIST" },
+    { MKD_ALT_AS_TITLE,   "ALT_AS_TITLE" },
 };
 #define NR(x)	(sizeof x/sizeof x[0])
 

generate.c

@@ -559,7 +559,9 @@ typedef struct linkytype {
 } linkytype;
 
 static linkytype imaget = { 0, 0, "<img src=\"", "\"",
-			     1, " alt=\"", "\" />", { { [MKD_NOIMAGE] = 1, [MKD_TAGTEXT] = 1} }, IS_URL };
+			     1, " alt=\"", "\" />", { { [MKD_NOIMAGE] = 1,
+							[MKD_TAGTEXT] = 1,
+							[MKD_ALT_AS_TITLE] = 1 } }, IS_URL };
 static linkytype linkt  = { 0, 0, "<a href=\"", "\"",
 			     0, ">", "</a>", { {[MKD_NOLINKS] = 1} }, IS_URL };
 
@@ -728,9 +730,12 @@ linkyformat(MMIOT *f, Cstring text, int image, Footnote *ref)
 	    if ( ref->width ) Qprintf(f, " width=\"%d\"", ref->width);
 	}
 
-	if ( S(ref->title) ) {
+	if ( S(ref->title) || (is_flag_set(&f->flags, MKD_ALT_AS_TITLE) && is_flag_set(&tag->flags, MKD_ALT_AS_TITLE)) ) {
 	    Qstring(" title=\"", f);
+	    if ( S(ref->title) )
 		___mkd_reparse(T(ref->title), S(ref->title), &tagtext, f, 0);
+	    else
+		___mkd_reparse(T(text), S(text), &tagtext, f, 0);
 	    Qchar('"', f);
 	}
 

markdown.h

@@ -43,6 +43,7 @@ enum {  MKD_NOLINKS=0,		/* don't do link processing, block <a> tags  */
 	MKD_GITHUBTAGS,		/* allow dash and underscore in element names */
 	MKD_URLENCODEDANCHOR,	/* urlencode non-identifier chars instead of replacing with dots */
 	MKD_LATEX,		/* handle embedded LaTeX escapes */
+	MKD_ALT_AS_TITLE,	/* use alt text as the title if no title is listed */
 			/* end of user flags */
 	IS_LABEL,
 	MKD_NR_FLAGS };

mkdio.h.in

@@ -40,6 +40,7 @@ enum {  MKD_NOLINKS=0,		/* don't do link processing, block <a> tags  */
 	MKD_GITHUBTAGS,		/* allow dash and underscore in element names */
 	MKD_URLENCODEDANCHOR,	/* urlencode non-identifier chars instead of replacing with dots */
 	MKD_LATEX,		/* handle embedded LaTeX escapes */
+	MKD_ALT_AS_TITLE,	/* use alt text as the title if no title is listed */
 	MKD_NR_FLAGS };
 
 /* abstract flag type */

pgm_options.c

@@ -78,6 +78,7 @@ static struct _opt {
     { "regular-listitem","github-style check items", 0, 0, 1, 1, MKD_NORMAL_LISTITEM } ,
     { "definitionlist","both discount & markdown extra definition lists", 1 },
     { "dlist",         "both discount & markdown extra definition lists", 1, 0, 1 },
+    { "alt_as_title",  "use the alt text as a title if there isn't one (images)", 0, 0, 0, 1, MKD_ALT_AS_TITLE },
 } ;
 
 #define NR(x)	(sizeof x / sizeof x[0])