From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 22 Jun 2013 16:43:39 +0000 (-0700)
Subject: * process.c (wait_reading_process_output): Avoid int overflow
X-Git-Tag: emacs-24.3.90~173^2^2~42^2~45^2~387^2~2002
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=f86852b4a3c34213f93fc5de5cb1632b49962023;p=emacs.git

* process.c (wait_reading_process_output): Avoid int overflow

when reading more than 2 GiB total from a process.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index bdb8baf65d8..36709eb5107 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2013-06-22  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* process.c (wait_reading_process_output): Avoid int overflow
+	when reading more than 2 GiB total from a process.
+
 2013-06-21  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* process.c (create_process): Handle a couple more cases,
diff --git a/src/process.c b/src/process.c
index c61a22c4beb..0631cb732bf 100644
--- a/src/process.c
+++ b/src/process.c
@@ -4430,7 +4430,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 	  && ! EQ (wait_proc->status, Qrun)
 	  && ! EQ (wait_proc->status, Qconnect))
 	{
-	  int nread, total_nread = 0;
+	  bool read_some_bytes = 0;
 
 	  clear_waiting_for_input ();
 	  XSETPROCESS (proc, wait_proc);
@@ -4438,16 +4438,13 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 	  /* Read data from the process, until we exhaust it.  */
 	  while (wait_proc->infd >= 0)
 	    {
-	      nread = read_process_output (proc, wait_proc->infd);
+	      int nread = read_process_output (proc, wait_proc->infd);
 
 	      if (nread == 0)
 		break;
 
 	      if (nread > 0)
-		{
-		  total_nread += nread;
-		  got_some_input = 1;
-		}
+		got_some_input = read_some_bytes = 1;
 	      else if (nread == -1 && (errno == EIO || errno == EAGAIN))
 		break;
 #ifdef EWOULDBLOCK
@@ -4455,7 +4452,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
 		break;
 #endif
 	    }
-	  if (total_nread > 0 && do_display)
+	  if (read_some_bytes && do_display)
 	    redisplay_preserve_echo_area (10);
 
 	  break;