bugfix: change the encoding bash uses for exported functions

This is upstream's patch:
Patch-ID:       bash42-050

This patch changes the encoding bash uses for exported functions to avoid
clashes with shell variables and to avoid depending only on an environment
variable's contents to determine whether or not to interpret it as a shell
function.

Change-Id: I594d4267e726453839d4ced9d36978a6fd84ee8d

1 files changed, 60 insertions, 20 deletions

diff --git a/variables.c b/variables.c
index 6b8ead1..9159133 100644
--- a/variables.c
+++ b/variables.c
@@ -79,6 +79,11 @@
 
 #define ifsname(s)	((s)[0] == 'I' && (s)[1] == 'F' && (s)[2] == 'S' && (s)[3] == '\0')
 
+#define BASHFUNC_PREFIX		"BASH_FUNC_"
+#define BASHFUNC_PREFLEN	10	/* == strlen(BASHFUNC_PREFIX */
+#define BASHFUNC_SUFFIX		"%%"
+#define BASHFUNC_SUFFLEN	2	/* == strlen(BASHFUNC_SUFFIX) */
+
 extern char **environ;
 
 /* Variables used here and defined in other files. */
@@ -268,7 +273,7 @@ static void push_temp_var __P((PTR_T));
 static void propagate_temp_var __P((PTR_T));
 static void dispose_temporary_env __P((sh_free_func_t *));     
 
-static inline char *mk_env_string __P((const char *, const char *));
+static inline char *mk_env_string __P((const char *, const char *, int));
 static char **make_env_array_from_var_list __P((SHELL_VAR **));
 static char **make_var_export_array __P((VAR_CONTEXT *));
 static char **make_func_export_array __P((void));
@@ -338,27 +343,41 @@ initialize_shell_variables (env, privmode)
 
       /* If exported function, define it now.  Don't import functions from
 	 the environment in privileged mode. */
-      if (privmode == 0 && read_but_dont_execute == 0 && STREQN ("() {", string, 4))
+      if (privmode == 0 && read_but_dont_execute == 0 &&
+	  STREQN (BASHFUNC_PREFIX, name, BASHFUNC_PREFLEN) &&
+	  STREQ (BASHFUNC_SUFFIX, name + char_index - BASHFUNC_SUFFLEN) &&
+	  STREQN ("() {", string, 4))
 	{
+	  size_t namelen;
+	  char *tname;		/* desired imported function name */
+
+	  namelen = char_index - BASHFUNC_PREFLEN - BASHFUNC_SUFFLEN;
+
+	  tname = name + BASHFUNC_PREFLEN;	/* start of func name */
+	  tname[namelen] = '\0';		/* now tname == func name */
+
 	  string_length = strlen (string);
-	  temp_string = (char *)xmalloc (3 + string_length + char_index);
+	  temp_string = (char *)xmalloc (namelen + string_length + 2);
 
-	  strcpy (temp_string, name);
-	  temp_string[char_index] = ' ';
-	  strcpy (temp_string + char_index + 1, string);
+	  memcpy (temp_string, tname, namelen);
+	  temp_string[namelen] = ' ';
+	  memcpy (temp_string + namelen + 1, string, string_length + 1);
 
 	  /* Don't import function names that are invalid identifiers from the
 	     environment. */
-	  if (legal_identifier (name))
-	    parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_FUNCDEF|SEVAL_ONECMD);
+	  if (absolute_program (tname) == 0 && (posixly_correct == 0 || legal_identifier (tname)))
+	    parse_and_execute (temp_string, tname, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_FUNCDEF|SEVAL_ONECMD);
 
-	  if (temp_var = find_function (name))
+	  if (temp_var = find_function (tname))
 	    {
 	      VSETATTR (temp_var, (att_exported|att_imported));
 	      array_needs_making = 1;
 	    }
 	  else
-	    report_error (_("error importing function definition for `%s'"), name);
+	    report_error (_("error importing function definition for `%s'"), tname);
+
+	  /* Restore original suffix */
+	  tname[namelen] = BASHFUNC_SUFFIX[0];
 	}
 #if defined (ARRAY_VARS)
 #  if 0
@@ -2537,7 +2556,7 @@ assign_in_env (word, flags)
   var->context = variable_context;	/* XXX */
 
   INVALIDATE_EXPORTSTR (var);
-  var->exportstr = mk_env_string (name, value);
+  var->exportstr = mk_env_string (name, value, 0);
 
   array_needs_making = 1;
 
@@ -3389,21 +3408,42 @@ merge_temporary_env ()
 /* **************************************************************** */
 
 static inline char *
-mk_env_string (name, value)
+mk_env_string (name, value, isfunc)
      const char *name, *value;
+     int isfunc;
 {
-  int name_len, value_len;
-  char	*p;
+  size_t name_len, value_len;
+  char	*p, *q;
 
   name_len = strlen (name);
   value_len = STRLEN (value);
-  p = (char *)xmalloc (2 + name_len + value_len);
-  strcpy (p, name);
-  p[name_len] = '=';
+
+  /* If we are exporting a shell function, construct the encoded function
+     name. */
+  if (isfunc && value)
+    {
+      p = (char *)xmalloc (BASHFUNC_PREFLEN + name_len + BASHFUNC_SUFFLEN + value_len + 2);
+      q = p;
+      memcpy (q, BASHFUNC_PREFIX, BASHFUNC_PREFLEN);
+      q += BASHFUNC_PREFLEN;
+      memcpy (q, name, name_len);
+      q += name_len;
+      memcpy (q, BASHFUNC_SUFFIX, BASHFUNC_SUFFLEN);
+      q += BASHFUNC_SUFFLEN;
+    }
+  else
+    {
+      p = (char *)xmalloc (2 + name_len + value_len);
+      memcpy (p, name, name_len);
+      q = p + name_len;
+    }
+
+  q[0] = '=';
   if (value && *value)
-    strcpy (p + name_len + 1, value);
+    memcpy (q + 1, value, value_len + 1);
   else
-    p[name_len + 1] = '\0';
+    q[1] = '\0';
+
   return (p);
 }
 
@@ -3489,7 +3529,7 @@ make_env_array_from_var_list (vars)
 	  /* Gee, I'd like to get away with not using savestring() if we're
 	     using the cached exportstr... */
 	  list[list_index] = USE_EXPORTSTR ? savestring (value)
-					   : mk_env_string (var->name, value);
+					   : mk_env_string (var->name, value, function_p (var));
 
 	  if (USE_EXPORTSTR == 0)
 	    SAVE_EXPORTSTR (var, list[list_index]);