From 206726fbfdd521fbb184daedb71b85030453bf0b Mon Sep 17 00:00:00 2001
From: Sergio Durigan Junior <sergiodj@redhat.com>
Date: Aug 15 2017 17:49:18 +0000
Subject: Fix PR gdb/21954: make 'unset environment' work again


When I made commit 9a6c7d9c021cfeb290d76584db7a01e57e7c3d4e, which
C++-fied gdb/common/environ.[ch], I mistakenly altered the behaviour
of the 'unset environment' command.  This command, which should delete
all environment variables, is now resetting the list of variables to
the state they were when GDB was started.

This commit fixes this regression, and also adds a test on
gdb.base/environ.exp which really checks if 'unset environment'
worked.

gdb/ChangeLog:
2017-08-15  Sergio Durigan Junior  <sergiodj@redhat.com>

	PR gdb/21954
	* infcmd.c (unset_environment_command): Use the 'clear' method on
	the environment instead of resetting it.

gdb/testsuite/ChangeLog:
2017-08-15  Sergio Durigan Junior  <sergiodj@redhat.com>

	PR gdb/21954
	* gdb.base/environ.exp: Add test to check if 'unset environment'
	works.

---

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index fbf14dd..94155f5 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-15  Sergio Durigan Junior  <sergiodj@redhat.com>
+
+	PR gdb/21954
+	* infcmd.c (unset_environment_command): Use the 'clear' method on
+	the environment instead of resetting it.
+
 2017-08-15  John Baldwin  <jhb@FreeBSD.org>
 
 	* fbsd-nat.c (fbsd_convert_siginfo): Fix compile on big-endian
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index defa7b0..c8a82db 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -2230,7 +2230,7 @@ unset_environment_command (char *var, int from_tty)
       /* If there is no argument, delete all environment variables.
          Ask for confirmation if reading from the terminal.  */
       if (!from_tty || query (_("Delete all environment variables? ")))
-	current_inferior ()->environment = gdb_environ::from_host_environ ();
+	current_inferior ()->environment.clear ();
     }
   else
     current_inferior ()->environment.unset (var);
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index f9494af..39c49b8 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-15  Sergio Durigan Junior  <sergiodj@redhat.com>
+
+	PR gdb/21954
+	* gdb.base/environ.exp: Add test to check if 'unset environment'
+	works.
+
 2017-08-14  Andreas Arnez  <arnez@linux.vnet.ibm.com>
 
 	* lib/gdb.exp (universal_compile_options): New caching proc.
diff --git a/gdb/testsuite/gdb.base/environ.exp b/gdb/testsuite/gdb.base/environ.exp
index 0b69a80..bb52063 100644
--- a/gdb/testsuite/gdb.base/environ.exp
+++ b/gdb/testsuite/gdb.base/environ.exp
@@ -46,6 +46,9 @@ gdb_test "unset environment" "" "unset all environment variables" \
     "Delete all environment variables. .y or n. $" \
     "y"
 
+gdb_test_no_output "show environment" \
+    "all environment variables have been unset"
+
 # Verify that we can set a specific environment variable.
 test_set_show_env_var "EDITOR" "emacs" "set environment variable"