From 2b0c045b635e108602a614beb8bf8343c4d21102 Mon Sep 17 00:00:00 2001
From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Fri, 1 Mar 2002 13:17:45 +0000
Subject: [PATCH] from_backend() should always be called with len > 0. Only
 rlogin mode ever failed to do this, and only Plink actually had a problem
 with it, so this didn't become obvious for a while. rlogin mode is fixed, and
 all implementations of from_backend() now contain an assertion so that we
 should spot errors of this type more quickly in future.

git-svn-id: svn://svn.tartarus.org/sgt/putty@1571 cda61777-01e9-0310-a592-d414129be87e
---
 plink.c    | 3 +++
 psftp.c    | 2 ++
 rlogin.c   | 3 ++-
 scp.c      | 2 ++
 terminal.c | 2 ++
 5 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/plink.c b/plink.c
index b7a2fd4b..b2c07acc 100644
--- a/plink.c
+++ b/plink.c
@@ -8,6 +8,7 @@
 #include <windows.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <assert.h>
 #include <stdarg.h>
 
 #define PUTTY_DO_GLOBALS	       /* actually _define_ globals */
@@ -147,6 +148,8 @@ int from_backend(int is_stderr, char *data, int len)
     HANDLE h = (is_stderr ? errhandle : outhandle);
     int osize, esize;
 
+    assert(len > 0);
+
     if (is_stderr) {
 	bufchain_add(&stderr_data, data, len);
 	try_output(1);
diff --git a/psftp.c b/psftp.c
index ead86140..094e68b0 100644
--- a/psftp.c
+++ b/psftp.c
@@ -1512,6 +1512,8 @@ int from_backend(int is_stderr, char *data, int datalen)
     unsigned char *p = (unsigned char *) data;
     unsigned len = (unsigned) datalen;
 
+    assert(len > 0);
+
     /*
      * stderr data is just spouted to local stderr and otherwise
      * ignored.
diff --git a/rlogin.c b/rlogin.c
index ba7dd37b..a80d12e3 100644
--- a/rlogin.c
+++ b/rlogin.c
@@ -68,7 +68,8 @@ static int rlogin_receive(Plug plug, int urgent, char *data, int len)
 	    }
 	    firstbyte = 0;
 	}
-	c_write(data, len);
+	if (len > 0)
+            c_write(data, len);
     }
     return 1;
 }
diff --git a/scp.c b/scp.c
index 60ca11cb..34f6ffb5 100644
--- a/scp.c
+++ b/scp.c
@@ -268,6 +268,8 @@ int from_backend(int is_stderr, char *data, int datalen)
     unsigned char *p = (unsigned char *) data;
     unsigned len = (unsigned) datalen;
 
+    assert(len > 0);
+
     /*
      * stderr data is just spouted to local stderr and otherwise
      * ignored.
diff --git a/terminal.c b/terminal.c
index 1c817dac..d76d7349 100644
--- a/terminal.c
+++ b/terminal.c
@@ -3603,6 +3603,8 @@ int term_ldisc(int option)
  */
 int from_backend(int is_stderr, char *data, int len)
 {
+    assert(len > 0);
+
     bufchain_add(&inbuf, data, len);
 
     /*
-- 
2.11.0