mdocml: The function term_flushln() had effectively forked in OpenBSD.

mdocml: The function term_flushln() had effectively forked in OpenBSD.

[kristaps]

Log Message:
-----------
The function term_flushln() had effectively forked in OpenBSD.
This is the bsd.lv part of the main step to bring it back in sync.
At the same time, this prevents trailing whitespace in the output:
We delay writing blanks until we are sure printable characters follow.

This is achieved by
* remembering the end of the word instead of its length
* and not using vbl any longer for the control of line breaking
* such that vbl can sum up all kinds of white space
* before writing a word, printing all the blanks collected in vbl
* within the word, adding NBSP chars to vbl, then continuing with the word
* after the word, adding blanks to vbl, then starting the next word

"looks good" kristaps@

Modified Files:
--------------
    mdocml:
        term.c

Revision Data
-------------
Index: term.c
===================================================================
RCS file: /usr/vhosts/mdocml.bsd.lv/cvs/mdocml/term.c,v
retrieving revision 1.135
retrieving revision 1.136
diff -Lterm.c -Lterm.c -u -p -r1.135 -r1.136
--- term.c
+++ term.c
@@ -133,7 +133,7 @@ term_flushln(struct termp *p)
 	int		 i;     /* current input position in p->buf */
 	size_t		 vis;   /* current visual position on output */
 	size_t		 vbl;   /* number of blanks to prepend to output */
-	size_t		 vsz;   /* visual characters to write to output */
+	size_t		 vend;	/* end of word visual position on output */
 	size_t		 bp;    /* visual right border position */
 	int		 j;     /* temporary loop index */
 	size_t		 maxvis, mmax;
@@ -156,25 +156,19 @@ term_flushln(struct termp *p)
 
 	bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
 
+	/*
+	 * Indent the first line of a paragraph.
+	 */
+	vbl = p->flags & TERMP_NOLPAD ? 0 : p->offset;
+
 	/* 
 	 * FIXME: if bp is zero, we still output the first word before
 	 * breaking the line.
 	 */
 
-	vis = 0;
-
-	/*
-	 * If in the standard case (left-justified), then begin with our
-	 * indentation, otherwise (columns, etc.) just start spitting
-	 * out text.
-	 */
-
-	if ( ! (p->flags & TERMP_NOLPAD))
-		/* LINTED */
-		for (j = 0; j < (int)p->offset; j++)
-			putchar(' ');
+	vis = vend = i = 0;
+	while (i < (int)p->col) {
 
-	for (i = 0; i < (int)p->col; i++) {
 		/*
 		 * Count up visible word characters.  Control sequences
 		 * (starting with the CSI) aren't counted.  A space
@@ -183,39 +177,28 @@ term_flushln(struct termp *p)
 		 */
 
 		/* LINTED */
-		for (j = i, vsz = 0; j < (int)p->col; j++) {
+		for (j = i; j < (int)p->col; j++) {
 			if (j && ' ' == p->buf[j]) 
 				break;
 			if (8 == p->buf[j])
-				vsz--;
+				vend--;
 			else
-				vsz++;
+				vend++;
 		}
 
 		/*
-		 * Choose the number of blanks to prepend: no blank at the
-		 * beginning of a line, one between words -- but do not
-		 * actually write them yet.
-		 */
-
-		vbl = (size_t)(0 == vis ? 0 : 1);
-
-		/*
 		 * Find out whether we would exceed the right margin.
-		 * If so, break to the next line.  Otherwise, write the chosen
-		 * number of blanks.
+		 * If so, break to the next line.
 		 */
-
-		if (vis && vis + vbl + vsz > bp) {
+		if (vend > bp && vis > 0) {
+			vend -= vis;
 			putchar('\n');
 			if (TERMP_NOBREAK & p->flags) {
 				for (j = 0; j < (int)p->rmargin; j++)
 					putchar(' ');
-				vis = p->rmargin - p->offset;
+				vend += p->rmargin - p->offset;
 			} else {
-				for (j = 0; j < (int)p->offset; j++)
-					putchar(' ');
-				vis = 0;
+				vbl = p->offset;
 			}
 
 			/* Remove the p->overstep width. */
@@ -223,22 +206,36 @@ term_flushln(struct termp *p)
 			bp += (int)/* LINTED */
 				p->overstep;
 			p->overstep = 0;
-		} else {
-			for (j = 0; j < (int)vbl; j++)
-				putchar(' ');
-			vis += vbl;
 		}
 
 		/* Write out the [remaining] word. */
-		for ( ; i < (int)p->col; i++)
-			if (' ' == p->buf[i])
+		for ( ; i < (int)p->col; i++) {
+			if (' ' == p->buf[i]) {
+				while (' ' == p->buf[i]) {
+					vbl++;
+					i++;
+				}
 				break;
-			else if (ASCII_NBRSP == p->buf[i])
-				putchar(' ');
-			else
-				putchar(p->buf[i]);
+			}
+			if (ASCII_NBRSP == p->buf[i]) {
+				vbl++;
+				continue;
+			}
 
-		vis += vsz;
+			/*
+			 * Now we definitely know there will be
+			 * printable characters to output,
+			 * so write preceding white space now.
+			 */
+			if (vbl) {
+				for (j = 0; j < (int)vbl; j++)
+					putchar(' ');
+				vbl = 0;
+			}
+			putchar(p->buf[i]);
+		}
+		vend += vbl;
+		vis = vend;
 	}
 
 	p->col = 0;
--
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