From 3fee777ec5a2e91ffbd9b396e99edae386eb150e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20E=C3=9Fer?= <se@FreeBSD.org>
Date: Sat, 26 Dec 2020 22:10:54 +0100
Subject: [PATCH] Simplify LS_COLWIDTHS processing

The previous version normalized the width list (replaced empty fields
with "0") just to be able to use sscanf() on the string.

It is much simpler to just parse the string as-is.

The clearing of f_notabs is preserved for the case that less than 9
width values have been defined, but I do not understand the rationale
for this particular condition. E.g., LS_COLWIDTHS="::::::::" will be
counted as 9 defined fields (may clear f_notabs) but is no different
fron LS_COLWIDTHS="" with regard to the field width (and that does not
clear f_notabs, since there are less than 9 fields).
---
 bin/ls/ls.c | 115 ++++++++++++++++++++--------------------------------
 1 file changed, 43 insertions(+), 72 deletions(-)

diff --git a/bin/ls/ls.c b/bin/ls/ls.c
index b0fe8d79e3ea..338b3d1d2a26 100644
--- a/bin/ls/ls.c
+++ b/bin/ls/ls.c
@@ -51,6 +51,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/ioctl.h>
 #include <sys/mac.h>
 
+#include <ctype.h>
 #include <dirent.h>
 #include <err.h>
 #include <errno.h>
@@ -88,12 +89,12 @@ __FBSDID("$FreeBSD$");
  */
 #define MAKENINES(n)							\
 	do {								\
-		intmax_t i;						\
+		intmax_t __i;						\
 									\
 		/* Use a loop as all values of n are small. */		\
-		for (i = 1; n > 0; i *= 10)				\
+		for (__i = 1; n > 0; __i *= 10)				\
 			n--;						\
-		n = i - 1;						\
+		n = __i - 1;						\
 	} while(0)
 
 static void	 display(const FTSENT *, FTSENT *, int);
@@ -715,88 +716,58 @@ display(const FTSENT *p, FTSENT *list, int options)
 	char *flags, *labelstr = NULL;
 	char ngroup[STRBUF_SIZEOF(uid_t) + 1];
 	char nuser[STRBUF_SIZEOF(gid_t) + 1];
+	u_long width[9];
+	int i;
 
 	needstats = f_inode || f_longform || f_size;
 	flen = 0;
 	btotal = 0;
-	initmax = getenv("LS_COLWIDTHS");
-	/* Fields match -lios order.  New ones should be added at the end. */
-	maxlabelstr = maxblock = maxlen = maxnlink = 0;
-	maxuser = maxgroup = maxflags = maxsize = 0;
-	maxinode = 0;
-	if (initmax != NULL && *initmax != '\0') {
-		char *initmax2, *jinitmax;
-		int ninitmax;
 
-		/* Fill-in "::" as "0:0:0" for the sake of scanf. */
-		jinitmax = malloc(strlen(initmax) * 2 + 2);
-		if (jinitmax == NULL)
-			err(1, "malloc");
-		initmax2 = jinitmax;
-		if (*initmax == ':')
-			strcpy(initmax2, "0:"), initmax2 += 2;
-		else
-			*initmax2++ = *initmax, *initmax2 = '\0';
-		for (initmax++; *initmax != '\0'; initmax++) {
-			if (initmax[-1] == ':' && initmax[0] == ':') {
-				*initmax2++ = '0';
-				*initmax2++ = initmax[0];
-				initmax2[1] = '\0';
+#define LS_COLWIDTHS_FIELDS	9
+	initmax = getenv("LS_COLWIDTHS");
+
+	for (i = 0 ; i < LS_COLWIDTHS_FIELDS; i++)
+		width[i] = 0;
+
+	if (initmax != NULL) {
+		char *endp;
+
+		for (i = 0; i < LS_COLWIDTHS_FIELDS && *initmax != '\0'; i++) {
+			if (*initmax == ':') {
+				width[i] = 0;
 			} else {
-				*initmax2++ = initmax[0];
-				initmax2[1] = '\0';
+				width[i] = strtoul(initmax, &endp, 10);
+				initmax = endp;
+				while (isspace(*initmax))
+					initmax++;
+				if (*initmax != ':')
+					break;
+				initmax++;
 			}
 		}
-		if (initmax2[-1] == ':')
-			strcpy(initmax2, "0");
-
-		ninitmax = sscanf(jinitmax,
-		    " %ju : %ld : %lu : %u : %u : %i : %jd : %lu : %lu ",
-		    &maxinode, &maxblock, &maxnlink, &maxuser,
-		    &maxgroup, &maxflags, &maxsize, &maxlen, &maxlabelstr);
-		f_notabs = 1;
-		switch (ninitmax) {
-		case 0:
-			maxinode = 0;
-			/* FALLTHROUGH */
-		case 1:
-			maxblock = 0;
-			/* FALLTHROUGH */
-		case 2:
-			maxnlink = 0;
-			/* FALLTHROUGH */
-		case 3:
-			maxuser = 0;
-			/* FALLTHROUGH */
-		case 4:
-			maxgroup = 0;
-			/* FALLTHROUGH */
-		case 5:
-			maxflags = 0;
-			/* FALLTHROUGH */
-		case 6:
-			maxsize = 0;
-			/* FALLTHROUGH */
-		case 7:
-			maxlen = 0;
-			/* FALLTHROUGH */
-		case 8:
-			maxlabelstr = 0;
-			/* FALLTHROUGH */
+		if (i < LS_COLWIDTHS_FIELDS)
 #ifdef COLORLS
 			if (!f_color)
 #endif
 				f_notabs = 0;
-			/* FALLTHROUGH */
-		default:
-			break;
-		}
-		MAKENINES(maxinode);
-		MAKENINES(maxblock);
-		MAKENINES(maxnlink);
-		MAKENINES(maxsize);
-		free(jinitmax);
 	}
+
+	/* Fields match -lios order.  New ones should be added at the end. */
+	maxinode = width[0];
+	maxblock = width[1];
+	maxnlink = width[2];
+	maxuser = width[3];
+	maxgroup = width[4];
+	maxflags = width[5];
+	maxsize = width[6];
+	maxlen = width[7];
+	maxlabelstr = width[8];
+
+	MAKENINES(maxinode);
+	MAKENINES(maxblock);
+	MAKENINES(maxnlink);
+	MAKENINES(maxsize);
+
 	d.s_size = 0;
 	sizelen = 0;
 	flags = NULL;