sbase-box: Fix segmentation fault when exe without args

when sbase-box is executed without argument, the check sbase-box
options doesn't verify the argument count leading to a segfault.

Add a check on the argc before parsing sbase-box options (currently
only `-i`)

TODO

@@ -28,10 +28,6 @@ Bugs
 
 ed
 --
-* Multi-line commands don't work in global commands:
-    g/^line/a \
-    line1
-    .
 * cat <<EOF | ed
     0a
     int radix = 16;
@@ -54,19 +50,16 @@ ed
     line
     .
     1g/^$/p
+* cat <<EOF | ed
+i
+foobar1
+foobar2
+.
+1,2s/foo/&\
+&/
+,n
+
 * Editing huge files doesn't work well.
-* Escaping newlines in replacement doesn't work well:
-	% /bin/ed
-	i
-	foobar
-	.
-	s/foo/&\
-	->
-	->bar
-	,p
-	foo
-	->bar
-	Q
 
 
 printf

ed.c

@@ -64,30 +64,15 @@ static int pflag, modflag, uflag, gflag;
 static size_t csize;
 static String cmdline;
 static char *ocmdline;
-static int repidx;
+static int inputidx;
 static char *rhs;
 static char *lastmatch;
 static struct undo udata;
 static int newcmd;
-int eol, bol;
+static int eol, bol;
 
 static sig_atomic_t intr, hup;
 
-static void
-discard(void)
-{
-	int c;
-
-	if (repidx >= 0 || cmdline.siz == 0)
-		return;
-
-	/* discard until the end of the line */
-	if (cmdline.str[cmdline.siz-1] != '\n') {
-		while ((c = getchar()) != '\n' && c != EOF)
-			;
-	}
-}
-
 static void undo(void);
 
 static void
@@ -102,7 +87,6 @@ error(char *msg)
 	if (!newcmd)
 		undo();
 
-	discard();
 	curln = ocurln;
 	longjmp(savesp, 1);
 }
@@ -121,6 +105,24 @@ prevln(int line)
 	return (line < 0) ? lastln : line;
 }
 
+static String *
+copystring(String *s, char *from)
+{
+	size_t len;
+	char *t;
+
+	if ((t = strdup(from)) == NULL)
+		error("out of memory");
+	len = strlen(t);
+
+	free(s->str);
+	s->str = t;
+	s->siz = len;
+	s->cap = len;
+
+	return s;
+}
+
 static String *
 string(String *s)
 {
@@ -154,30 +156,22 @@ static void chksignals(void);
 static int
 input(void)
 {
-	int c;
-
-	if (repidx >= 0)
-		return ocmdline[repidx++];
-
-	if ((c = getchar()) != EOF)
-		addchar(c, &cmdline);
+	int ch;
 
 	chksignals();
 
-	return c;
+	ch = cmdline.str[inputidx];
+	if (ch != '\0')
+		inputidx++;
+	return ch;
 }
 
 static int
 back(int c)
 {
-	if (repidx > 0) {
-		--repidx;
-	} else {
-		ungetc(c, stdin);
-		if (c != EOF)
-			--cmdline.siz;
-	}
-	return c;
+	if (c == '\0')
+		return c;
+	return cmdline.str[--inputidx] = c;
 }
 
 static int
@@ -185,25 +179,27 @@ makeline(char *s, int *off)
 {
 	struct hline *lp;
 	size_t len;
-	char c, *begin = s;
+	char *begin = s;
+	int c;
 
 	if (lastidx >= idxsize) {
 		lp = NULL;
 		if (idxsize <= SIZE_MAX - NUMLINES)
-		    lp = reallocarray(zero, idxsize + NUMLINES, sizeof(*lp));
+			lp = reallocarray(zero, idxsize + NUMLINES, sizeof(*lp));
 		if (!lp)
 			error("out of memory");
 		idxsize += NUMLINES;
 		zero = lp;
 	}
 	lp = zero + lastidx;
+	lp->global = 0;
 
 	if (!s) {
 		lp->seek = -1;
 		len = 0;
 	} else {
-		while ((c = *s++) != '\n')
-			/* nothing */;
+		while ((c = *s++) && c != '\n')
+			;
 		len = s - begin;
 		if ((lp->seek = lseek(scratch, 0, SEEK_END)) < 0 ||
 		    write(scratch, begin, len) < 0) {
@@ -408,18 +404,14 @@ compile(int delim)
 
 	eol = bol = bracket = lastre.siz = 0;
 	for (n = 0;; ++n) {
-		if ((c = input()) == delim && !bracket)
+		c = input();
+		if (c == delim && !bracket || c == '\0') {
 			break;
-		if (c == '^') {
+		} else if (c == '^') {
 			bol = 1;
 		} else if (c == '$') {
 			eol = 1;
-		} else if (c == '\n' || c == EOF) {
-			back(c);
-			break;
-		}
-
-		if (c == '\\') {
+		} else if (c == '\\') {
 			addchar(c, &lastre);
 			c = input();
 		} else if (c == '[') {
@@ -490,7 +482,7 @@ skipblank(void)
 	char c;
 
 	while ((c = input()) == ' ' || c == '\t')
-		/* nothing */;
+		;
 	back(c);
 }
 
@@ -503,9 +495,8 @@ ensureblank(void)
 	case ' ':
 	case '\t':
 		skipblank();
-	case '\n':
+	case '\0':
 		back(c);
-	case EOF:
 		break;
 	default:
 		error("unknown command");
@@ -663,6 +654,55 @@ quit(void)
 	exit(exstatus);
 }
 
+static void
+setinput(char *s)
+{
+	copystring(&cmdline, s);
+	inputidx = 0;
+}
+
+static void
+getinput(void)
+{
+	int ch;
+
+	string(&cmdline);
+
+	while ((ch = getchar()) != '\n' && ch != EOF) {
+		if (ch == '\\') {
+			if ((ch = getchar()) == EOF)
+				break;
+			if (ch != '\n') {
+				ungetc(ch, stdin);
+				ch = '\\';
+			}
+		}
+		addchar(ch, &cmdline);
+	}
+
+	addchar('\0', &cmdline);
+	inputidx = 0;
+
+	if (ch == EOF) {
+		chksignals();
+		if (ferror(stdin)) {
+			exstatus = 1;
+			fputs("ed: error reading input\n", stderr);
+		}
+		quit();
+	}
+}
+
+static int
+moreinput(void)
+{
+	if (!uflag)
+		return cmdline.str[inputidx] != '\0';
+
+	getinput();
+	return 1;
+}
+
 static void dowrite(const char *, int);
 
 static void
@@ -670,6 +710,9 @@ dump(void)
 {
 	char *home;
 
+	if (modflag)
+		return;
+
 	line1 = nextln(0);
 	line2 = lastln;
 
@@ -690,14 +733,14 @@ static void
 chksignals(void)
 {
 	if (hup) {
-		if (modflag)
-			dump();
 		exstatus = 1;
+		dump();
 		quit();
 	}
 
 	if (intr) {
 		intr = 0;
+		newcmd = 1;
 		clearerr(stdin);
 		error("Interrupt");
 	}
@@ -846,7 +889,7 @@ dohelp(void)
 static void
 chkprint(int flag)
 {
-	char c;
+	int c;
 
 	if (flag) {
 		if ((c = input()) == 'p' || c == 'l' || c == 'n')
@@ -854,12 +897,12 @@ chkprint(int flag)
 		else
 			back(c);
 	}
-	if (input() != '\n')
+	if ((c = input()) != '\0' && c != '\n')
 		error("invalid command suffix");
 }
 
 static char *
-getfname(char comm)
+getfname(int comm)
 {
 	int c;
 	char *bp;
@@ -867,7 +910,7 @@ getfname(char comm)
 
 	skipblank();
 	for (bp = fname; bp < &fname[FILENAME_MAX]; *bp++ = c) {
-		if ((c = input()) == EOF || c == '\n')
+		if ((c = input()) == '\0')
 			break;
 	}
 	if (bp == fname) {
@@ -889,16 +932,21 @@ getfname(char comm)
 static void
 append(int num)
 {
-	char *s = NULL;
-	size_t len = 0;
+	int ch;
+	static String line;
 
 	curln = num;
-	while (getline(&s, &len, stdin) > 0) {
-		if (*s == '.' && s[1] == '\n')
+	while (moreinput()) {
+		string(&line);
+		while ((ch = input()) != '\n' && ch != '\0')
+			addchar(ch, &line);
+		addchar('\n', &line);
+		addchar('\0', &line);
+
+		if (!strcmp(line.str, ".\n") || !strcmp(line.str, "."))
 			break;
-		inject(s, AFTER);
+		inject(line.str, AFTER);
 	}
-	free(s);
 }
 
 static void
@@ -1022,14 +1070,22 @@ execsh(void)
 		error("no previous command");
 	}
 
-	while ((c = input()) != EOF && c != '\n') {
-		if (c == '%' && (cmd.siz == 0 || cmd.str[cmd.siz - 1] != '\\')) {
+	while ((c = input()) != '\0') {
+		switch (c) {
+		case '%':
 			if (savfname[0] == '\0')
 				error("no current filename");
 			repl = 1;
 			for (p = savfname; *p; ++p)
 				addchar(*p, &cmd);
-		} else {
+			break;
+		case '\\':
+			c = input();
+			if (c != '%') {
+				back(c);
+				c = '\\';
+			}
+		default:
 			addchar(c, &cmd);
 		}
 	}
@@ -1049,20 +1105,18 @@ getrhs(int delim)
 	static String s;
 
 	string(&s);
-	while ((c = input()) != '\n' && c != EOF && c != delim)
+	while ((c = input()) != '\0' && c != delim)
 		addchar(c, &s);
 	addchar('\0', &s);
-	if (c == EOF)
-		error("invalid pattern delimiter");
-	if (c == '\n') {
+	if (c == '\0') {
 		pflag = 'p';
 		back(c);
 	}
 
 	if (!strcmp("%", s.str)) {
-		free(s.str);
 		if (!rhs)
 			error("no previous substitution");
+		free(s.str);
 	} else {
 		free(rhs);
 		rhs = s.str;
@@ -1183,8 +1237,7 @@ subst(int nth)
 static void
 docmd(void)
 {
-	char cmd;
-	int rep = 0, c, line3, num, trunc;
+	int cmd, c, line3, num, trunc;
 
 repeat:
 	skipblank();
@@ -1196,21 +1249,16 @@ repeat:
 		chkprint(0);
 		if (!ocmdline)
 			error("no previous command");
-		rep = 1;
-		repidx = 0;
+		setinput(ocmdline);
 		getlst();
 		goto repeat;
 	case '!':
 		execsh();
 		break;
-	case EOF:
-		if (cmdline.siz == 0)
-			quit();
-	case '\n':
-		if (gflag && uflag)
-			return;
+	case '\0':
 		num = gflag ? curln : curln+1;
 		deflines(num, num);
+		line1 = line2;
 		pflag = 'p';
 		goto print;
 	case 'l':
@@ -1360,7 +1408,7 @@ repeat:
 		ensureblank();
 		if (nlines > 0)
 			goto unexpected;
-		if (back(input()) != '\n')
+		if (back(input()) != '\0')
 			getfname(cmd);
 		else
 			puts(savfname);
@@ -1392,21 +1440,11 @@ repeat:
 	}
 
 	if (!pflag)
-		goto save_last_cmd;
-
+		return;
 	line1 = line2 = curln;
+
 print:
 	doprint();
-
-save_last_cmd:
-	if (!uflag)
-		repidx = 0;
-	if (rep)
-		return;
-	free(ocmdline);
-	addchar('\0', &cmdline);
-	if ((ocmdline = strdup(cmdline.str)) == NULL)
-		error("out of memory");
 }
 
 static int
@@ -1451,12 +1489,26 @@ chkglobal(void)
 }
 
 static void
-doglobal(void)
+savecmd(void)
 {
-	int cnt, ln, k;
+	int ch;
+
+	skipblank();
+	ch = input();
+	if (ch != '&') {
+		ocmdline = strdup(cmdline.str);
+		if (ocmdline == NULL)
+			error("out of memory");
+	}
+	back(ch);
+}
+
+static void
+doglobal(void)
+{
+	int cnt, ln, k, idx;
 
 	skipblank();
-	string(&cmdline);
 	gflag = 1;
 	if (uflag)
 		chkprint(0);
@@ -1469,19 +1521,33 @@ doglobal(void)
 			zero[k].global = 0;
 			curln = ln;
 			nlines = 0;
-			if (uflag) {
-				line1 = line2 = ln;
-				pflag = 0;
-				doprint();
+
+			if (!uflag) {
+				idx = inputidx;
+				getlst();
+				docmd();
+				inputidx = idx;
+				continue;
 			}
-			getlst();
-			docmd();
+
+			line1 = line2 = ln;
+			pflag = 0;
+			doprint();
+
+			for (;;) {
+				getinput();
+				if (strcmp(cmdline.str, "") == 0)
+					break;
+				savecmd();
+				getlst();
+				docmd();
+			}
+
 		} else {
 			cnt++;
 			ln = nextln(ln);
 		}
 	}
-	discard();   /* cover the case of not matching anything */
 }
 
 static void
@@ -1509,12 +1575,12 @@ edit(void)
 		newcmd = 1;
 		ocurln = curln;
 		olastln = lastln;
-		cmdline.siz = 0;
-		repidx = -1;
 		if (optprompt) {
 			fputs(prompt, stdout);
 			fflush(stdout);
 		}
+
+		getinput();
 		getlst();
 		chkglobal() ? doglobal() : docmd();
 	}

scripts/mkbox

@@ -76,7 +76,7 @@ main(int argc, char *argv[])
 	char *s = basename(argv[0]);
 	struct cmd *bp;
 
-	if(!strcmp(s,"sbase-box")) {
+	if (!strcmp(s, "sbase-box") && argc > 1) {
 		argc--; argv++;
 		if (strcmp(argv[0], "-i") == 0) {
 			install(argv[1]);