textproc/htdig: fix build on armv7

Work around a polymorphism error by using monomorphic fabs() instead
of fabs().

textproc/htdig/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	htdig
 PORTVERSION=	3.2.0.b6
-PORTREVISION=	6
+PORTREVISION=	7
 CATEGORIES=	textproc www
 MASTER_SITES=	SF/${PORTNAME}/${PORTNAME}/3.2.0b6
 DISTNAME=	htdig-3.2.0b6

textproc/htdig/files/patch-htsearch_Display.cc

@@ -0,0 +1,20 @@
+--- htsearch/Display.cc.orig	2023-04-10 13:24:24 UTC
++++ htsearch/Display.cc
+@@ -42,7 +42,7 @@ using namespace std;
+ #endif /* HAVE_STD */
+ 
+ #include <stdio.h>
+-#include <stdlib.h> // for abs
++#include <math.h> // for fabs
+ #include <ctype.h>
+ 
+ #ifndef _MSC_VER /* _WIN32 */
+@@ -1541,7 +1541,7 @@ Display::buildMatchList()
+ // seconds in a 365 days year). The formula gives less weight
+ // as the distance between the date document and the current time
+ // increases (the absolute value is for documents with future date)
+-#define DATE_FACTOR(df, n, dd) ((df) * 100 / (1+(double)(abs((n) - (dd)) / 31536000)))
++#define DATE_FACTOR(df, n, dd) ((df) * 100 / (1+(double)(fabs((n) - (dd)) / 31536000)))
+ 	    date_score =  DATE_FACTOR(date_factor, now, thisRef->DocTime());
+ 	    score += date_score;
+         }