Store the initial working directory, expand $initial_cwd. Bug 1805

(cherry picked from commit 3615fa9a06356891367c66ed284cef9db5cefca3)
(cherry picked from commit fae3a611be53dbf58cbb7c2c4846081ecb87606e)

6 files changed, 21 insertions, 2 deletions

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 6a1963043..046a17f3b 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -11612,6 +11612,12 @@ See &$host_lookup_deferred$&.
 This variable is set to the remote host's TCP port whenever &$host$& is set
 for an outbound connection.
 
+.vitem &$initial_cwd$&
+.vindex "&$initial_cwd$&
+This variable contains the full path name of the initial working
+directory of the current Exim process. This may differ from the current
+working directory, as Exim changes this to "/" during early startup, and
+to &$spool_directory$& later.
 
 .vitem &$inode$&
 .vindex "&$inode$&"
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index a0002b620..0f164c301 100644
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -6,6 +6,8 @@ Before a formal release, there may be quite a lot of detail so that people can
 test from the snapshots or the CVS before the documentation is updated. Once
 the documentation is updated, this file is reduced to a short list.
 
+ 9. New $initial_cwd expansion variable.
+
 Version 4.86
 ------------
 
diff --git a/src/src/exim.c b/src/src/exim.c
index beb5abc25..022b840fb 100644
--- a/src/src/exim.c
+++ b/src/src/exim.c
@@ -3730,6 +3730,13 @@ if (Uchdir("/") < 0)
     exit(EXIT_FAILURE);
   }
 
+/* Store the initial cwd before we change directories */
+if ((initial_cwd = getcwd(NULL, 0)) == NULL)
+  {
+  perror("exim: can't get the current working directory");
+  exit(EXIT_FAILURE);
+  }
+
 readconf_main();
 
 if (cleanup_environment() == FALSE)
@@ -4017,9 +4024,10 @@ if (((debug_selector & D_any) != 0 || (log_extra_selector & LX_arguments) != 0)
   {
   int i;
   uschar *p = big_buffer;
-  char * dummy;
   Ustrcpy(p, "cwd= (failed)");
-  dummy = /* quieten compiler */ getcwd(CS p+4, big_buffer_size - 4);
+
+  Ustrncpy(p + 4, initial_cwd, big_buffer_size-5);
+
   while (*p) p++;
   (void)string_format(p, big_buffer_size - (p - big_buffer), " %d args:", argc);
   while (*p) p++;
diff --git a/src/src/expand.c b/src/src/expand.c
index 89e0ac779..6f07f2203 100644
--- a/src/src/expand.c
+++ b/src/src/expand.c
@@ -533,6 +533,7 @@ static var_entry var_table[] = {
   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
   { "host_port",           vtype_int,         &deliver_host_port },
+  { "initial_cwd",         vtype_stringptr,   &initial_cwd },
   { "inode",               vtype_ino,         &deliver_inode },
   { "interface_address",   vtype_stringptr,   &interface_address },
   { "interface_port",      vtype_int,         &interface_port },
diff --git a/src/src/globals.c b/src/src/globals.c
index 1dbc015f0..1d5752d33 100644
--- a/src/src/globals.c
+++ b/src/src/globals.c
@@ -783,6 +783,7 @@ BOOL    ignore_fromline_local  = FALSE;
 uschar *ignore_fromline_hosts  = NULL;
 BOOL    inetd_wait_mode        = FALSE;
 int     inetd_wait_timeout     = -1;
+uschar *initial_cwd            = NULL;
 uschar *interface_address      = NULL;
 int     interface_port         = -1;
 BOOL    is_inetd               = FALSE;
diff --git a/src/src/globals.h b/src/src/globals.h
index f3e884b8e..bb1c0edcb 100644
--- a/src/src/globals.h
+++ b/src/src/globals.h
@@ -508,6 +508,7 @@ extern BOOL    ignore_fromline_local;  /* Local SMTP ignore fromline */
 extern uschar *ignore_fromline_hosts;  /* Hosts permitted to send "From " */
 extern BOOL    inetd_wait_mode;        /* Whether running in inetd wait mode */
 extern int     inetd_wait_timeout;     /* Timeout for inetd wait mode */
+extern uschar *initial_cwd;            /* The directory we where in at startup */
 extern BOOL    is_inetd;               /* True for inetd calls */
 extern uschar *iterate_item;           /* Item from iterate list */