Fix PR gdb/17035: "show user" doesn't list user-defined commands that have empty bodies.

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index b415267..b0f1bdf 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -1245,8 +1245,7 @@  show_user (char *args, int from_tty)
       const char *comname = args;
 
       c = lookup_cmd (&comname, cmdlist, "", 0, 1);
-      /* c->user_commands would be NULL if it's a python/scheme command.  */
-      if (c->class != class_user || !c->user_commands)
+      if (!cli_user_command_p (c))
 	error (_("Not a user command."));
       show_user_1 (c, "", args, gdb_stdout);
     }
@@ -1254,7 +1253,7 @@  show_user (char *args, int from_tty)
     {
       for (c = cmdlist; c; c = c->next)
 	{
-	  if (c->class == class_user || c->prefixlist != NULL)
+	  if (cli_user_command_p (c) || c->prefixlist != NULL)
 	    show_user_1 (c, "", c->name, gdb_stdout);
 	}
     }
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index c409d9c..914a8e3 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -1884,3 +1884,10 @@  cmd_func (struct cmd_list_element *cmd, char *args, int from_tty)
   else
     error (_("Invalid command"));
 }
+
+int
+cli_user_command_p (struct cmd_list_element *cmd)
+{
+  return (cmd->class == class_user
+	  && (cmd->func == do_cfunc || cmd->func == do_sfunc));
+}
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index 865d4a0..41ce299 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -233,4 +233,9 @@  extern void print_doc_line (struct ui_file *, const char *);
 
 extern const char * const auto_boolean_enums[];
 
+/* Verify whether a given cmd_list_element is a user-defined command.
+   Return 1 if it is user-defined.  Return 0 otherwise.  */
+
+int cli_user_command_p (struct cmd_list_element *);
+
 #endif /* !defined (CLI_DECODE_H) */
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 0f0a97e..37cb82a 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -1717,10 +1717,10 @@  show_user_1 (struct cmd_list_element *c, const char *prefix, const char *name,
     }
 
   cmdlines = c->user_commands;
-  if (!cmdlines)
-    return;
   fprintf_filtered (stream, "User command \"%s%s\":\n", prefix, name);
 
+  if (!cmdlines)
+    return;
   print_command_lines (current_uiout, cmdlines, 1);
   fputs_filtered ("\n", stream);
 }
diff --git a/gdb/testsuite/gdb.base/commands.exp b/gdb/testsuite/gdb.base/commands.exp
index 7363420..74eb306 100644
--- a/gdb/testsuite/gdb.base/commands.exp
+++ b/gdb/testsuite/gdb.base/commands.exp
@@ -243,6 +243,28 @@  proc user_defined_command_test {} {
    gdb_test "show user mycommand" \
 	"  while \\\$arg0.*set.*    if \\\(\\\$arg0.*p/x.*    else\[^\n\].*p/x.*    end\[^\n\].*  end\[^\n\].*" \
 	   "display user command in user_defined_command_test"
+
+    # Create and test a user-defined command with an empty body.
+    gdb_test_multiple "define myemptycommand" \
+	"define myemptycommand in user_defined_command_test" {
+	    -re "End with"  {
+		pass "define myemptycommand in user_defined_command_test"
+	    }
+	}
+    gdb_test "end" \
+	"" \
+	"end definition of user-defined command with empty body"
+
+    gdb_test_no_output "myemptycommand" \
+	"execute user-defined empty command in user_defined_command_test"
+
+    gdb_test "show user" \
+	"User command \"myemptycommand.*" \
+	"display empty command in command list in user_defined_command_test"
+
+    gdb_test "show user myemptycommand" \
+	"User command \"myemptycommand.*" \
+	"display user-defined empty command in user_defined_command_test"
 }
 
 proc watchpoint_command_test {} {
diff --git a/gdb/testsuite/gdb.guile/scm-cmd.exp b/gdb/testsuite/gdb.guile/scm-cmd.exp
index a407f63..13ce9c2 100644
--- a/gdb/testsuite/gdb.guile/scm-cmd.exp
+++ b/gdb/testsuite/gdb.guile/scm-cmd.exp
@@ -134,6 +134,10 @@  gdb_test "help user-defined" \
     "User-defined commands.\[\r\n\]+The commands in this class are those defined by the user.\[\r\n\]+Use the \"define\" command to define a command.\[\r\n\]+List of commands:\[\r\n\]+test-help -- Docstring\[\r\n\]+Type \"help\" followed by command name for full documentation.\[\r\n\]+Type \"apropos word\" to search for commands related to \"word\".\[\r\n\]+Command name abbreviations are allowed if unambiguous.\[\r\n\]+" \
     "see user-defined command in `help user-defined`"
 
+# Make sure the command does not show up in `show user`.
+gdb_test "show user test-help" "Not a user command\." \
+    "don't show user-defined scheme command in `show user command`"
+
 # Test expression completion on fields.
 
 gdb_test_multiline "expression completion command" \
diff --git a/gdb/testsuite/gdb.python/py-cmd.exp b/gdb/testsuite/gdb.python/py-cmd.exp
index a87aecb..c84401f 100644
--- a/gdb/testsuite/gdb.python/py-cmd.exp
+++ b/gdb/testsuite/gdb.python/py-cmd.exp
@@ -161,6 +161,10 @@  gdb_test "test_help ugh" "test_cmd output, arg = ugh" "call simple user-defined
 # Make sure the command shows up in `help user-defined`.
 gdb_test "help user-defined" "User-defined commands.\[\r\n\]+The commands in this class are those defined by the user.\[\r\n\]+Use the \"define\" command to define a command.\[\r\n\]+\[\r\n\]+List of commands:\[\r\n\]+\[\r\n\]+test_help -- Docstring\[\r\n\]+\[\r\n\]+Type \"help\" followed by command name for full documentation.\[\r\n\]+Type \"apropos word\" to search for commands related to \"word\".\[\r\n\]+Command name abbreviations are allowed if unambiguous.\[\r\n\]+" "see user-defined command in `help user-defined`"
 
+# Make sure the command does not show up in `show user`.
+gdb_test "show user test_help" "Not a user command\." \
+    "don't show user-defined python command in `show user command`"
+
 # Test expression completion on fields
 gdb_py_test_multiple "expression completion command" \
   "python" "" \