X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/blobdiff_plain/3d88e64dfcf5dc0fd361ce0c504c67a9196ce44c..72e8da4264659149cce87bf8e757f8cdb3d4ba0f:/misc.c

diff --git a/misc.c b/misc.c
index 3fea3746..1bd556e6 100644
--- a/misc.c
+++ b/misc.c
@@ -1,3 +1,7 @@
+/*
+ * Platform-independent routines shared between all PuTTY programs.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
@@ -11,9 +15,12 @@
 
 char *dupstr(const char *s)
 {
-    int len = strlen(s);
-    char *p = snewn(len + 1, char);
-    strcpy(p, s);
+    char *p = NULL;
+    if (s) {
+        int len = strlen(s);
+        p = snewn(len + 1, char);
+        strcpy(p, s);
+    }
     return p;
 }
 
@@ -178,6 +185,8 @@ void bufchain_add(bufchain *ch, const void *data, int len)
 {
     const char *buf = (const char *)data;
 
+    if (len == 0) return;
+
     ch->buffersize += len;
 
     if (ch->tail && ch->tail->buflen < BUFFER_GRANULE) {