* usr/bin/byobu-select-session: LP: #1241785

- rework session selecting, especially when nesting
  - support an environment variable BYOBU_NESTING=1 which users can
    set to force nesting (rather than modifying the TERM variable
    which other programs rely upon)
  - add an interactive step, where users can immediately choose to
    run in a nested session

debian/changelog

@@ -7,6 +7,13 @@ byobu (5.61) unreleased; urgency=low
     usr/share/byobu/pixmaps/byobu.svg:
     - add a new banner image
     - use a green color for the branches in the logo
+  * usr/bin/byobu-select-session: LP: #1241785
+    - rework session selecting, especially when nesting
+    - support an environment variable BYOBU_NESTING=1 which users can
+      set to force nesting (rather than modifying the TERM variable
+      which other programs rely upon)
+    - add an interactive step, where users can immediately choose to
+      run in a nested session
 
  -- Dustin Kirkland <kirkland@ubuntu.com>  Sat, 21 Sep 2013 09:42:30 -0500
 

usr/bin/byobu-select-session

@@ -30,7 +30,7 @@ SHELL = os.getenv("SHELL", "/bin/bash")
 HOME = os.getenv("HOME")
 BYOBU_CONFIG_DIR = os.getenv("BYOBU_CONFIG_DIR", HOME + "/.byobu")
 BYOBU_BACKEND = os.getenv("BYOBU_BACKEND", "tmux")
-choice = ""
+choice = -1
 sessions = []
 text = []
 
@@ -96,6 +96,24 @@ def attach_session(session):
 	else:
 		os.execvp("screen", ["", "-AOxRR", session_name])
 
+# Confirm nested session, if necessary
+if os.getenv("BYOBU_NESTING", "0") != "1":
+	if (BYOBU_BACKEND == "tmux" and os.getenv("TMUX")) or (BYOBU_BACKEND == "screen" and "screen" in os.getenv("TERM")):
+		sys.stderr.write("WARNING: Sessions should be nested with care.\n")
+		try:
+			nest = raw_input("Are you sure you want to run Byobu inside another session?  [y/N]: ")
+			if nest != "Y" and nest != "y":
+				sys.exit(1)
+			else:
+				if os.getenv("TMUX"):
+					os.unsetenv("TMUX")
+		except KeyboardInterrupt:
+			sys.stdout.write("\n")
+			sys.exit(1)
+		except:
+			sys.stdout.write("\n")
+			sys.exit(1)
+
 sessions = get_sessions()
 
 show_shell = os.path.exists("%s/.always-select" % (BYOBU_CONFIG_DIR))
@@ -119,29 +137,23 @@ if len(sessions) > 1:
 				break
 			else:
 				tries += 1
-				choice = ""
+				choice = -1
 				sys.stderr.write("\nERROR: Invalid input\n")
 		except KeyboardInterrupt:
-			print()
+			sys.stdout.write("\n")
 			sys.exit(0)
 		except:
-			if choice == "":
+			if choice == "" or choice == -1:
 				choice = 1
 				break
 			tries += 1
-			choice = ""
+			choice = -1
 			sys.stderr.write("\nERROR: Invalid input\n")
 elif len(sessions) == 1:
 	# Auto-select the only session
 	choice = 1
-	if BYOBU_BACKEND == "tmux" and os.getenv("TMUX"):
-		sys.stderr.write("ERROR: Sessions should be nested with care. Unset $TMUX to force.\n")
-		sys.exit(1)
-	elif BYOBU_BACKEND == "screen" and re.match("screen", os.getenv("TERM")):
-		sys.stderr.write("ERROR: Sessions should be nested with care. Remove 'screen' from $TERM to force.\n")
-		sys.exit(1)
 
-if choice:
+if choice >= 1:
 	if sessions[choice - 1] == "NEW":
 		# Create a new session
 		if BYOBU_BACKEND == "tmux":