* cygheap.cc (cygheap_fixup_in_child): Drop call to set_dll_dir.

	(init_cygheap::init_installation_root): Set installation_dir_len.
	(setup_cygheap): Drop call to set_dll_dir.
	* cygheap.h (struct init_cygheap): Add installation_dir_len member.
	(init_cygheap::set_dll_dir): Remove.
	* environ.cc (win_env::add_cache): Use stpcpy for speed.
	(posify_maybe): Use tmp_pathbuf buffer instead of stack.
	(raise_envblock): New function to resize Windows environment block.
	(build_env): Fix indentation.  Call raise_envblock function.  Check if
	$PATH exists and is non-empty.  If not, add PATH variable with Cygwin
	installation directory as content to Windows environment.  Explain why.

	* uinfo.cc (cygheap_pwdgrp::_nss_init): Fill UNICODE_STRING members
	on the fly.  Drop call to RtlInitUnicodeString.
	(pwdgrp::check_file): Ditto.

6 files changed, 87 insertions, 53 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 79f32e7ca..69d37e89b 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,21 @@
+2014-10-27  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygheap.cc (cygheap_fixup_in_child): Drop call to set_dll_dir.
+	(init_cygheap::init_installation_root): Set installation_dir_len.
+	(setup_cygheap): Drop call to set_dll_dir.
+	* cygheap.h (struct init_cygheap): Add installation_dir_len member.
+	(init_cygheap::set_dll_dir): Remove.
+	* environ.cc (win_env::add_cache): Use stpcpy for speed.
+	(posify_maybe): Use tmp_pathbuf buffer instead of stack.
+	(raise_envblock): New function to resize Windows environment block.
+	(build_env): Fix indentation.  Call raise_envblock function.  Check if
+	$PATH exists and is non-empty.  If not, add PATH variable with Cygwin
+	installation directory as content to Windows environment.  Explain why.
+
+	* uinfo.cc (cygheap_pwdgrp::_nss_init): Fill UNICODE_STRING members
+	on the fly.  Drop call to RtlInitUnicodeString.
+	(pwdgrp::check_file): Ditto.
+
 2014-10-26  Corinna Vinschen  <corinna@vinschen.de>
 
 	* fhandler_socket.cc (fhandler_socket::af_local_connect): Drop
diff --git a/winsup/cygwin/cygheap.cc b/winsup/cygwin/cygheap.cc
index 8e25a07ea..97090affc 100644
--- a/winsup/cygwin/cygheap.cc
+++ b/winsup/cygwin/cygheap.cc
@@ -83,7 +83,6 @@ cygheap_fixup_in_child (bool execed)
   _csbrk ((char *) child_proc_info->cygheap_max - (char *) cygheap);
   child_copy (child_proc_info->parent, false, "cygheap", cygheap, cygheap_max, NULL);
   cygheap_init ();
-  cygheap->set_dll_dir ();
   debug_fixup_after_fork_exec ();
   if (execed)
     {
@@ -188,9 +187,10 @@ init_cygheap::init_installation_root ()
 	       "Invalid DLL path");
 
   /* Copy result into installation_dir before stripping off "bin" dir and
-     revert to Win32 path.  This path is used in cygheap_init to call
-     SetDllDirectory. */
-  wcpncpy (installation_dir, installation_root, PATH_MAX);
+     revert to Win32 path.  This path is added to the Windows environment
+     in buildenv.  See there for a description. */
+  installation_dir_len = wcpncpy (installation_dir, installation_root, PATH_MAX)
+			 - installation_dir;
   installation_dir[1] = L'\\';
 
   /* If w < p, the Cygwin DLL resides in the root dir of a drive or network
@@ -264,7 +264,6 @@ setup_cygheap ()
   cygheap_init ();
   cygheap->user.init ();
   cygheap->init_installation_root (); /* Requires user.init! */
-  cygheap->set_dll_dir ();
   cygheap->pg.init ();
 }
 
diff --git a/winsup/cygwin/cygheap.h b/winsup/cygwin/cygheap.h
index 55f26ed36..ff86d5ef3 100644
--- a/winsup/cygwin/cygheap.h
+++ b/winsup/cygwin/cygheap.h
@@ -506,6 +506,7 @@ struct init_cygheap: public mini_cygheap
   char *buckets[NBUCKETS];
   WCHAR installation_root[PATH_MAX];
   WCHAR installation_dir[PATH_MAX];
+  size_t installation_dir_len;
   UNICODE_STRING installation_key;
   WCHAR installation_key_buf[18];
   cygheap_root root;
@@ -534,15 +535,6 @@ struct init_cygheap: public mini_cygheap
   hook_chain hooks;
   void close_ctty ();
   void init_installation_root ();
-  void set_dll_dir ()
-  {
-    /* Call SetDllDirectory on installation_dir.  This removes "." from the
-       DLL search path and installs our /bin dir instead.
-       Amazing but true:  This setting is propagated to child processes :-)
-			  but only starting with Windows 8 :-( */
-    if (!SetDllDirectoryW (installation_dir))
-      debug_printf ("SetDllDirectoryW (%W), %E", installation_dir);
-  }
   void __reg1 init_tls_list ();;
   void __reg2 add_tls (_cygtls *);
   void __reg3 remove_tls (_cygtls *, DWORD);
diff --git a/winsup/cygwin/environ.cc b/winsup/cygwin/environ.cc
index 817439b0a..9b9be4a00 100644
--- a/winsup/cygwin/environ.cc
+++ b/winsup/cygwin/environ.cc
@@ -396,18 +396,15 @@ win_env::add_cache (const char *in_posix, const char *in_native)
   if (in_native)
     {
       native = (char *) realloc (native, namelen + 1 + strlen (in_native));
-      strcpy (native, name);
-      strcpy (native + namelen, in_native);
+      stpcpy (stpcpy (native, name), in_native);
     }
   else
     {
       tmp_pathbuf tp;
       char *buf = tp.c_get ();
-      strcpy (buf, name + namelen);
       towin32 (in_posix, buf, NT_MAX_PATH);
       native = (char *) realloc (native, namelen + 1 + strlen (buf));
-      strcpy (native, name);
-      strcpy (native + namelen, buf);
+      stpcpy (stpcpy (native, name), buf);
     }
   MALLOC_CHECK;
   if (immediate && cygwin_finished_initializing)
@@ -480,8 +477,9 @@ posify_maybe (char **here, const char *value, char *outenv)
     {
       /* The conversion routine removed elements from a path list so we have
 	 to recalculate the windows path to remove elements there, too. */
-      char cleanvalue[strlen (value) + 1];
-      conv->towin32 (newvalue, cleanvalue, sizeof cleanvalue);
+      tmp_pathbuf tp;
+      char *cleanvalue = tp.c_get ();
+      conv->towin32 (newvalue, cleanvalue, NT_MAX_PATH);
       conv->add_cache (newvalue, cleanvalue);
     }
 
@@ -1032,6 +1030,21 @@ spenv::retrieve (bool no_envblock, const char *const env)
   return getwinenveq (name, namelen, HEAP_1_STR);
 }
 
+static inline int
+raise_envblock (int new_tl, PWCHAR &envblock, PWCHAR &s)
+{
+  int tl = new_tl + 100;
+  PWCHAR new_envblock =
+	    (PWCHAR) realloc (envblock, (2 + tl) * sizeof (WCHAR));
+  /* If realloc moves the block, move `s' with it. */
+  if (new_envblock != envblock)
+    {
+      s += new_envblock - envblock;
+      envblock = new_envblock;
+    }
+  return tl;
+}
+
 #define SPENVS_SIZE (sizeof (spenvs) / sizeof (spenvs[0]))
 
 /* Create a Windows-style environment block, i.e. a typical character buffer
@@ -1096,14 +1109,14 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
   for (unsigned i = 0; i < SPENVS_SIZE; i++)
     if (!saw_spenv[i] && (spenvs[i].force_into_environment || cygheap->user.issetuid ()))
       {
-	  *dstp = spenvs[i].retrieve (false);
-	  if (*dstp && *dstp != env_dontadd)
-	    {
-	      *pass_dstp++ = *dstp;
-	      tl += strlen (*dstp) + 1;
-	      dstp++;
-	    }
-	}
+	*dstp = spenvs[i].retrieve (false);
+	if (*dstp && *dstp != env_dontadd)
+	  {
+	    *pass_dstp++ = *dstp;
+	    tl += strlen (*dstp) + 1;
+	    dstp++;
+	  }
+      }
 
   envc = dstp - newenv;		/* Number of entries in newenv */
   assert ((size_t) envc <= (n + SPENVS_SIZE));
@@ -1126,6 +1139,7 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
       PWCHAR s;
       envblock = (PWCHAR) malloc ((2 + tl) * sizeof (WCHAR));
       int new_tl = 0;
+      bool saw_PATH = false;
       for (srcp = pass_env, s = envblock; *srcp; srcp++)
 	{
 	  const char *p;
@@ -1144,7 +1158,17 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
 	  /* See if this entry requires posix->win32 conversion. */
 	  conv = getwinenv (*srcp, rest, &temp);
 	  if (conv)
-	    p = conv->native;	/* Use win32 path */
+	    {
+	      p = conv->native;	/* Use win32 path */
+	      /* Does PATH exist in the environment? */
+	      if (**srcp == 'P')
+		{
+		  /* And is it non-empty? */
+		  if (!conv->native || !conv->native[0])
+		    continue;
+		  saw_PATH = true;
+		}
+	    }
 	  else
 	    p = *srcp;		/* Don't worry about it */
 
@@ -1153,19 +1177,9 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
 
 	  /* See if we need to increase the size of the block. */
 	  if (new_tl > tl)
-	    {
-	      tl = new_tl + 100;
-	      PWCHAR new_envblock =
-			(PWCHAR) realloc (envblock, (2 + tl) * sizeof (WCHAR));
-	      /* If realloc moves the block, move `s' with it. */
-	      if (new_envblock != envblock)
-		{
-		  s += new_envblock - envblock;
-		  envblock = new_envblock;
-		}
-	    }
+	    tl = raise_envblock (new_tl, envblock, s);
 
-	  int slen = sys_mbstowcs (s, len, p);
+	  len = sys_mbstowcs (s, len, p);
 
 	  /* See if environment variable is "special" in a Windows sense.
 	     Under NT, the current directories for visited drives are stored
@@ -1174,7 +1188,17 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
 	  if (s[0] == L'!' && (iswdrive (s + 1) || (s[1] == L':' && s[2] == L':'))
 	      && s[3] == L'=')
 	    *s = L'=';
-	  s += slen + 1;
+	  s += len + 1;
+	}
+      /* If PATH doesn't exist in the environment, add a PATH with just
+	 Cygwin's bin dir to the Windows env to allow loading system DLLs
+	 during execve. */
+      if (!saw_PATH)
+	{
+	  new_tl += cygheap->installation_dir_len + 5;
+	  if (new_tl > tl)
+	    tl = raise_envblock (new_tl, envblock, s);
+	  s = wcpcpy (wcpcpy (s, L"PATH="), cygheap->installation_dir) + 1;
 	}
       *s = L'\0';			/* Two null bytes at the end */
       assert ((s - envblock) <= tl);	/* Detect if we somehow ran over end
diff --git a/winsup/cygwin/release/1.7.33 b/winsup/cygwin/release/1.7.33
index c64d2d3a1..c7acd071d 100644
--- a/winsup/cygwin/release/1.7.33
+++ b/winsup/cygwin/release/1.7.33
@@ -42,8 +42,9 @@ What changed:
   are supposed to work.  Finally implement a CLASS_OBJ emulation.  Update
   getfacl(1)/setfacl(1) accordingly.
 
-- Drop the current working directory from the default DLL search path in
-  favor of Cygwin's /bin dir.
+- When exec'ing applications, check if $PATH exists and is non-empty.  If not,
+  add PATH variable with Cygwin installation directory as content to Windows
+  environment to allow loading of Cygwin system DLLs.
 
 - Improve various header files for C++- and standards-compliance.
 
diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
index 12d5069d1..75b447287 100644
--- a/winsup/cygwin/uinfo.cc
+++ b/winsup/cygwin/uinfo.cc
@@ -752,10 +752,11 @@ cygheap_pwdgrp::_nss_init ()
   char *buf = tp.c_get ();
 
   PCWSTR rel_path = L"\\etc\\nsswitch.conf";
-  path.Buffer = (PWCHAR) alloca ((wcslen (cygheap->installation_root)
-				  + wcslen (rel_path) + 1) * sizeof (WCHAR));
+  path.Length = (wcslen (cygheap->installation_root) + wcslen (rel_path))
+		* sizeof (WCHAR);
+  path.MaximumLength = path.Length + sizeof (WCHAR);
+  path.Buffer = (PWCHAR) alloca (path.MaximumLength);
   wcpcpy (wcpcpy (path.Buffer, cygheap->installation_root), rel_path);
-  RtlInitUnicodeString (&path, path.Buffer);
   InitializeObjectAttributes (&attr, &path, OBJ_CASE_INSENSITIVE,
 			      NULL, NULL);
   if (rl.init (&attr, buf, NT_MAX_PATH))
@@ -1045,12 +1046,11 @@ pwdgrp::check_file ()
   if (!path.Buffer)
     {
       PCWSTR rel_path = is_group () ? L"\\etc\\group" : L"\\etc\\passwd";
-      path.Buffer = (PWCHAR) cmalloc_abort (HEAP_BUF,
-					    (wcslen (cygheap->installation_root)
-					     + wcslen (rel_path) + 1)
-					    * sizeof (WCHAR));
+      path.Length = (wcslen (cygheap->installation_root) + wcslen (rel_path))
+		    * sizeof (WCHAR);
+      path.MaximumLength = path.Length + sizeof (WCHAR);
+      path.Buffer = (PWCHAR) cmalloc_abort (HEAP_BUF, path.MaximumLength);
       wcpcpy (wcpcpy (path.Buffer, cygheap->installation_root), rel_path);
-      RtlInitUnicodeString (&path, path.Buffer);
       InitializeObjectAttributes (&attr, &path, OBJ_CASE_INSENSITIVE,
 				  NULL, NULL);
     }