Re: emacs & MAXPATHLEN

[Giuseppe Scrivano]

"Richard M. Stallman" <address@hidden> writes:

>     Shouldn't the MAXPATHLEN present in the emacs source code be
>     removed to avoid incompatibilities with hurd?
>
> Yes.  And we want to get rid of arbitrary limits anyway.
>
> I found only one place where MAXPATHLEN is used,
> aside from conditionals for specific proprietary systems.
> That is in init_buffer.  Would someone like to convert it
> to extend its buffer when needed?
Hi,
This little patch should fix it. If something is wrong comments are well 
accepted.

--- src/buffer.c.old    2005-07-28 19:14:42.000000000 +0200
+++ src/buffer.c        2005-07-29 02:21:03.000000000 +0200
@@ -5114,7 +5114,7 @@
 void
 init_buffer ()
 {
-  char buf[MAXPATHLEN + 1];
+  char *buf;
   char *pwd;
   struct stat dotstat, pwdstat;
   Lisp_Object temp;
@@ -5146,14 +5146,47 @@
       && stat (".", &dotstat) == 0
       && dotstat.st_ino == pwdstat.st_ino
       && dotstat.st_dev == pwdstat.st_dev
-      && strlen (pwd) < MAXPATHLEN)
-    strcpy (buf, pwd);
-#ifdef HAVE_GETCWD
-  else if (getcwd (buf, MAXPATHLEN+1) == 0)
-    fatal ("`getcwd' failed: %s\n", strerror (errno));
+#ifdef MAXPATHLEN
+      && strlen (pwd) < MAXPATHLEN
+#endif
+      )
+    {
+      buf = malloc(strlen(pwd)+1);
+      if(!buf)
+        fatal ("`malloc' failed in init_buffer\n");
+      strcpy (buf, pwd);
+    }
+#ifdef _GNU_SOURCE
+  else
+    {
+      buf = get_current_dir_name();
+      if(!buf)
+        fatal ("`get_current_dir_name' failed in init_buffer\n");
+    }
+#elif HAVE_GETCWD
+  else
+    {
+      buf = malloc(MAXPATHLEN+1);
+      if(!buf)
+        fatal ("`malloc' failed in init_buffer\n");
+      if(buf)
+        {
+          if(getcdwd (buf, MAXPATHLEN+1) == 0)
+            fatal ("`getwd' failed: %s\n", buf);
+        }
+    }
 #else
-  else if (getwd (buf) == 0)
-    fatal ("`getwd' failed: %s\n", buf);
+  else
+    {
+      buf = malloc(MAXPATHLEN+1);
+      if(!buf)
+        fatal ("`malloc' failed in init_buffer\n");
+      if(buf)
+        {
+          if(getwd (buf) == 0)
+            fatal ("`getwd' failed: %s\n", buf);
+        }
+    }
 #endif

 #ifndef VMS
@@ -5189,6 +5222,7 @@

   temp = get_minibuffer (0);
   XBUFFER (temp)->directory = current_buffer->directory;
+  free(buf);
 }

 /* initialize the buffer routines */



I worked on the xsmfns.c file too. I am not sure if this is required for the 
hurd compatibility.  


--- src/xsmfns.c.old    2005-07-28 19:51:24.000000000 +0200
+++ src/xsmfns.c        2005-07-28 21:30:11.000000000 +0200
@@ -56,7 +56,6 @@
 #define MAXPATHLEN 1024
 #endif /* not MAXPATHLEN */

-
 /* The user login name.  */

 extern Lisp_Object Vuser_login_name;
@@ -205,7 +204,7 @@
   int val_idx = 0;
   int props_idx = 0;

-  char cwd[MAXPATHLEN+1];
+  char *cwd = NULL;
   char *smid_opt;

   /* How to start a new instance of Emacs.  */
@@ -259,12 +258,28 @@
   props[props_idx]->vals[0].value = SDATA (Vuser_login_name);
   ++props_idx;

-  /* The current directory property, not mandatory.  */
-#ifdef HAVE_GETCWD
-  if (getcwd (cwd, MAXPATHLEN+1) != 0)
+#ifdef _GNU_SOURCE
+  cwd = get_current_dir_name();
+  if(!cwd)
+    fatal ("`get_current_dir_name' failed in smc_save_yourself_CB\n");
+#elif HAVE_GETCWD
+  cwd = malloc(MAXPATHLEN+1);
+  if(!cwd)
+    fatal ("`malloc' failed in failed in smc_save_yourself_CB\n");
+  if(cwd)
+    {
+      if(getcdwd (cwd, MAXPATHLEN+1) == 0)
+        fatal ("`getwd' failed: %s\n", cwd);
+    }
 #else
-  if (getwd (cwd) != 0)
+  cwd = malloc(MAXPATHLEN+1);
+  if(!cwd)
+    fatal ("`malloc' failed in smc_save_yourself_CB\n");
+  if(getwd (cwd) == 0)
+    fatal ("`getwd' failed: %s\n", cwd);
 #endif
+
+  if(!cwd)
     {
       props[props_idx] = &prop_ptr[props_idx];
       props[props_idx]->name = SmCurrentDirectory;
@@ -280,6 +295,7 @@
   SmcSetProperties (smcConn, props_idx, props);

   xfree (smid_opt);
+  free(cwd);

   /* See if we maybe shall interact with the user.  */
   if (interactStyle != SmInteractStyleAny


Regards,
Giuseppe Scrivano