1 files changed, 17 insertions, 3 deletions

diff --git a/src/callproc.c b/src/callproc.c
index b308644e7a3..5b321f1821f 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -200,7 +200,9 @@ If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.")
   int fd[2];
   int filefd;
   register int pid;
-  char buf[1024];
+  char buf[16384];
+  char *bufptr = buf;
+  int bufsize = 16384;
   int count = specpdl_ptr - specpdl;
   register unsigned char **new_argv
     = (unsigned char **) alloca ((max (2, nargs - 2)) * sizeof (char *));
@@ -493,8 +495,9 @@ If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.")
   {
     register int nread;
     int first = 1;
+    int total_read = 0;
 
-    while ((nread = read (fd[0], buf, sizeof buf)) != 0)
+    while ((nread = read (fd[0], bufptr, bufsize)) != 0)
       {
         if (nread < 0)
           {
@@ -505,8 +508,19 @@ If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.")
 #endif
           }
         immediate_quit = 0;
+        total_read += nread;
+        
         if (!NILP (buffer))
-          insert (buf, nread);
+          insert (bufptr, nread);
+
+        /* Make the buffer bigger as we continue to read more data,
+           but not past 64k.  */
+        if (bufsize < 64 * 1024 && total_read > 32 * bufsize)
+          {
+            bufsize *= 2;
+            bufptr = (char *) alloca (bufsize);
+          }
+
         if (!NILP (display) && INTERACTIVE)
           {
             if (first)