plan9port

commit edbdfca9ae880879e0830f8eaf2a37abaeca4b54
parent e96e50d8fbc20e52354d63c2c785e645918d082d
Author: ssnf <ssnf@ssnf.xyz>
Date:   Thu, 31 Jul 2025 08:02:02 +0000

fix libstr bugs

Diffstat:
M
src/libstr/Strdelete.c
 | 
2
++
M
src/libstr/Strgets.c
 | 
11
+++++++----
M
src/libstr/Strinsert.c
 | 
2
++

3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/src/libstr/Strdelete.c b/src/libstr/Strdelete.c
@@ -10,6 +10,8 @@ Strdelc(String *p)
 void
 Strdelete(String *p, Posn p0, Posn p1)
 {
+	if (p0 > p1 || p1 > p->n)
+		sysfatal("Strdelete: bad range");
 	memmove(p->s + p0, p->s + p1, p->n - p1);
 	p->n -= p1 - p0;
 	p->s[p->n] = '\0';
diff --git a/src/libstr/Strgets.c b/src/libstr/Strgets.c
@@ -4,12 +4,15 @@ int
 Strgets(String *p, Biobuf *b)
 {
 	char *s;
+	ulong n;
 
 	Strzero(p);
 	s = Brdline(b, '\n');
-	p->n = Blinelen(b);
-	if (p->n)
-		Stradds(p, Strn(s, p->n));
-	return p->n;
+	n = Blinelen(b);
+	if (n && s[n - 1] == '\n')
+		--n;
+	if (n)
+		Stradds(p, Strn(s, n));
+	return n;
 }
 
diff --git a/src/libstr/Strinsert.c b/src/libstr/Strinsert.c
@@ -3,6 +3,8 @@
 void
 Strinsert(String *p, String q, Posn p0)
 {
+	if (p0 > p->n)
+		sysfatal("Strinsert: bad position");
 	Strinsure(p, p->n + q.n);
 	memmove(p->s + p0 + q.n, p->s + p0, p->n - p0);
 	memmove(p->s + p0, q.s, q.n);