Merge PR #1649

7 files changed, 52 insertions, 11 deletions

diff --git a/doc/ranger.1 b/doc/ranger.1
index bccbfa98..f209f5fa 100644
--- a/doc/ranger.1
+++ b/doc/ranger.1
@@ -1,4 +1,4 @@
-.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35)
+.\" Automatically generated by Pod::Man 4.10 (Pod::Simple 3.35)
 .\"
 .\" Standard preamble:
 .\" ========================================================================
@@ -133,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "RANGER 1"
-.TH RANGER 1 "ranger-1.9.2" "25/07/19" "ranger manual"
+.TH RANGER 1 "ranger-1.9.2" "08/18/2019" "ranger manual"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
@@ -971,6 +971,13 @@ all directories above the current one as well?
 .IP "mouse_enabled [bool] <zm>" 4
 .IX Item "mouse_enabled [bool] <zm>"
 Enable mouse input?
+.IP "nested_ranger_warning [string]" 4
+.IX Item "nested_ranger_warning [string]"
+Warn at startup if \f(CW\*(C`RANGER_LEVEL\*(C'\fR is greater than 0, in other words give a
+warning when you nest ranger in a subshell started by ranger. Allowed values
+are \f(CW\*(C`true\*(C'\fR, \f(CW\*(C`false\*(C'\fR and \f(CW\*(C`error\*(C'\fR. The special value \f(CW\*(C`error\*(C'\fR promotes the
+warning to an error, this is usually shown as red text but will crash ranger
+when run with the \f(CW\*(C`\-\-debug\*(C'\fR flag.
 .IP "one_indexed [bool]" 4
 .IX Item "one_indexed [bool]"
 Start line numbers from 1.  Possible values are:
diff --git a/doc/ranger.pod b/doc/ranger.pod
index 0fd5cc47..4b44fc92 100644
--- a/doc/ranger.pod
+++ b/doc/ranger.pod
@@ -985,6 +985,14 @@ all directories above the current one as well?
 
 Enable mouse input?
 
+=item nested_ranger_warning [string]
+
+Warn at startup if C<RANGER_LEVEL> is greater than 0, in other words give a
+warning when you nest ranger in a subshell started by ranger. Allowed values
+are C<true>, C<false> and C<error>. The special value C<error> promotes the
+warning to an error, this is usually shown as red text but will crash ranger
+when run with the C<--debug> flag.
+
 =item one_indexed [bool]
 
 Start line numbers from 1.  Possible values are:
diff --git a/doc/rifle.1 b/doc/rifle.1
index a42734d2..114cc5d0 100644
--- a/doc/rifle.1
+++ b/doc/rifle.1
@@ -1,4 +1,4 @@
-.\" Automatically generated by Pod::Man 4.09 (Pod::Simple 3.35)
+.\" Automatically generated by Pod::Man 4.10 (Pod::Simple 3.35)
 .\"
 .\" Standard preamble:
 .\" ========================================================================
@@ -54,16 +54,20 @@
 .\" Avoid warning from groff about undefined register 'F'.
 .de IX
 ..
-.if !\nF .nr F 0
-.if \nF>0 \{\
-.    de IX
-.    tm Index:\\$1\t\\n%\t"\\$2"
+.nr rF 0
+.if \n(.g .if rF .nr rF 1
+.if (\n(rF:(\n(.g==0)) \{\
+.    if \nF \{\
+.        de IX
+.        tm Index:\\$1\t\\n%\t"\\$2"
 ..
-.    if !\nF==2 \{\
-.        nr % 0
-.        nr F 2
+.        if !\nF==2 \{\
+.            nr % 0
+.            nr F 2
+.        \}
 .    \}
 .\}
+.rr rF
 .\"
 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
 .\" Fear.  Run.  Save yourself.  No user-serviceable parts.
@@ -129,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "RIFLE 1"
-.TH RIFLE 1 "rifle-1.9.2" "2019-04-03" "rifle manual"
+.TH RIFLE 1 "rifle-1.9.2" "08/18/2019" "rifle manual"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
diff --git a/examples/rc_emacs.conf b/examples/rc_emacs.conf
index 0462282e..e3596ba5 100644
--- a/examples/rc_emacs.conf
+++ b/examples/rc_emacs.conf
@@ -206,6 +206,11 @@ set idle_delay 2000
 # check all directories above the current one as well?
 set metadata_deep_search false
 
+# Warn at startup if RANGER_LEVEL env var is greater than 0, in other words
+# give a warning when you nest ranger in a subshell started by ranger.
+# Special value "error" makes the warning more visible.
+set nested_ranger_warning true
+
 # ===================================================================
 # == Local Options
 # ===================================================================
diff --git a/ranger/config/rc.conf b/ranger/config/rc.conf
index f559290d..00a20def 100644
--- a/ranger/config/rc.conf
+++ b/ranger/config/rc.conf
@@ -301,6 +301,11 @@ set freeze_files false
 # Print file sizes in bytes instead of the default human-readable format.
 set size_in_bytes false
 
+# Warn at startup if RANGER_LEVEL env var is greater than 0, in other words
+# give a warning when you nest ranger in a subshell started by ranger.
+# Special value "error" makes the warning more visible.
+set nested_ranger_warning true
+
 # ===================================================================
 # == Local Options
 # ===================================================================
diff --git a/ranger/container/settings.py b/ranger/container/settings.py
index d15f8b3b..82901ac0 100644
--- a/ranger/container/settings.py
+++ b/ranger/container/settings.py
@@ -58,6 +58,7 @@ ALLOWED_SETTINGS = {
     'max_history_size': (int, type(None)),
     'metadata_deep_search': bool,
     'mouse_enabled': bool,
+    'nested_ranger_warning': str,
     'one_indexed': bool,
     'open_all_images': bool,
     'padding_right': bool,
@@ -105,6 +106,7 @@ ALLOWED_VALUES = {
     'confirm_on_delete': ['multiple', 'always', 'never'],
     'draw_borders': ['none', 'both', 'outline', 'separators'],
     'line_numbers': ['false', 'absolute', 'relative'],
+    'nested_ranger_warning': ['true', 'false', 'error'],
     'one_indexed': [False, True],
     'preview_images_method': ['w3m', 'iterm2', 'terminology',
                               'urxvt', 'urxvt-full', 'kitty',
diff --git a/ranger/core/main.py b/ranger/core/main.py
index 23648677..aefaacbc 100644
--- a/ranger/core/main.py
+++ b/ranger/core/main.py
@@ -180,6 +180,16 @@ def main(
             for command in args.cmd:
                 fm.execute_console(command)
 
+        if int(os.environ[level]) > 1:
+            warning = 'Warning:'
+            nested_warning = "You're in a nested ranger instance!"
+            warn_when_nested = fm.settings.nested_ranger_warning.lower()
+            if warn_when_nested == 'true':
+                fm.notify(' '.join((warning, nested_warning)), bad=False)
+            elif warn_when_nested == 'error':
+                fm.notify(' '.join((warning.upper(), nested_warning + '!!')),
+                          bad=True)
+
         if ranger.args.profile:
             import cProfile
             import pstats