From 87ef6d70e3a49ad6a83bb183c60fe07ba24c6741 Mon Sep 17 00:00:00 2001
From: Lutz Schwarz <Lutz.Schwarz@vetrontypical.com>
Date: Thu, 3 Sep 2020 15:05:57 +0200
Subject: [PATCH 1/3] Detect existing auto expander without using md5.

Make installation of auto expander more stable.
---
 pishrink.sh | 46 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 10 deletions(-)

diff --git a/pishrink.sh b/pishrink.sh
index dbf6b09..fadd90d 100755
--- a/pishrink.sh
+++ b/pishrink.sh
@@ -78,14 +78,8 @@ function set_autoexpand() {
         return
     fi
 
-    if [[ -f "$mountdir/etc/rc.local" ]] && [[ "$(md5sum "$mountdir/etc/rc.local" | cut -d ' ' -f 1)" != "1c579c7d5b4292fd948399b6ece39009" ]]; then
-      echo "Creating new /etc/rc.local"
-    if [ -f "$mountdir/etc/rc.local" ]; then
-        mv "$mountdir/etc/rc.local" "$mountdir/etc/rc.local.bak"
-    fi
-
-    #####Do not touch the following lines#####
-cat <<\EOF1 > "$mountdir/etc/rc.local"
+    local new_rc_local=$(
+cat <<\EOF1
 #!/bin/bash
 do_expand_rootfs() {
   ROOT_PART=$(mount | sed -n 's|^/dev/\(.*\) on / .*|\1|p')
@@ -146,8 +140,40 @@ if [[ -f /etc/rc.local.bak ]]; then
 fi
 exit 0
 EOF1
-    #####End no touch zone#####
-    chmod +x "$mountdir/etc/rc.local"
+)
+    if [[ ! -f "$mountdir/etc/rc.local" ]] || [[ "$(cat "$mountdir/etc/rc.local")" != "$new_rc_local" ]]; then
+      if [ -f "$mountdir/etc/rc.local" ]; then
+        if fgrep -q expand            "$mountdir/etc/rc.local" &&
+           fgrep -q /etc/rc.local     "$mountdir/etc/rc.local" &&
+           fgrep -q /etc/rc.local.bak "$mountdir/etc/rc.local"
+        then
+            info "Image already has autoexpander of different $MYNAME version: replacing autoexpander"
+            # In this case we replace /etc/rc.local but leave an existing rc.local.bak unchanged.
+        else
+          [ -e "$mountdir/etc/rc.local.bak" ] && mv -Tf "$mountdir/etc/rc.local.bak" "$mountdir/etc/rc.local.bak.bak" &&
+            info "Found unexpected /etc/rc.local.bak - renamed to /etc/rc.local.bak.bak"
+          # Save original /etc/rc.local to be executed after expand.
+          if ! mv -Tf "$mountdir/etc/rc.local" "$mountdir/etc/rc.local.bak"; then
+              info "WARNING: autoexpand could not be installed."
+              umount "$mountdir"
+              return
+          fi
+        fi
+      else
+        # No original /etc/rc.local exists; ensure we leave with a rc.local.bak that does nothing.
+        [ -e "$mountdir/etc/rc.local.bak" ] && mv -Tf "$mountdir/etc/rc.local.bak" "$mountdir/etc/rc.local.bak.bak" &&
+            info "Found unexpected /etc/rc.local.bak - renamed to /etc/rc.local.bak.bak"
+      fi
+
+      info "Creating new /etc/rc.local"
+      echo "$new_rc_local" > "$mountdir/etc/rc.local"
+      chmod +x "$mountdir/etc/rc.local"
+
+      # If no /etc/rc.local.bak exists, create one that does nothing.
+      if [ ! -e "$mountdir/etc/rc.local.bak" ]; then
+        cp /dev/null "$mountdir/etc/rc.local.bak"
+        chmod +x "$mountdir/etc/rc.local.bak"
+      fi
     fi
     umount "$mountdir"
 }

From 9db4e9b68bca4327730a123f2b90960ef5d88173 Mon Sep 17 00:00:00 2001
From: Lutz Schwarz <Lutz.Schwarz@vetrontypical.com>
Date: Thu, 3 Sep 2020 17:02:34 +0200
Subject: [PATCH 2/3] Ensure a console exists when booting for autoexpand to
 prevent start failure

---
 pishrink.sh | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/pishrink.sh b/pishrink.sh
index fadd90d..3c70801 100755
--- a/pishrink.sh
+++ b/pishrink.sh
@@ -81,6 +81,7 @@ function set_autoexpand() {
     local new_rc_local=$(
 cat <<\EOF1
 #!/bin/bash
+[ -f /boot/cmdline.txt.pishrink-bak ] && mv -fT /boot/cmdline.txt.pishrink-bak /boot/cmdline.txt
 do_expand_rootfs() {
   ROOT_PART=$(mount | sed -n 's|^/dev/\(.*\) on / .*|\1|p')
 
@@ -175,9 +176,54 @@ EOF1
         chmod +x "$mountdir/etc/rc.local.bak"
       fi
     fi
+
+    # If rc.local is started by systemd it may fail to start if no console exists.
+    # Ensure a console is there until autoexpand was done:
+    boot_enable_console "$mountdir"
+
     umount "$mountdir"
 }
 
+function boot_enable_console () {
+
+  local fsroot="$1"
+  local bootstart="$(echo "$parted_output" | grep '^1:' | cut -d ':' -f 2 | tr -d 'B')"
+  local boot bootloop bootroot
+  local SEDCMDS='s/console=null/console=tty0/'
+
+  if [ -z "$fsroot" -o "x$bootstart" != "x$partstart" ]
+  then
+    bootloop="$(losetup -f --show -o "$bootstart" "$img")"
+    bootroot="$(mktemp -d)"
+    partprobe "$bootloop"
+    mount "$bootloop" "$bootroot"
+    boot="$bootroot"
+  else
+    boot="$fsroot/boot"
+  fi
+
+  logVariables $LINENO fsroot bootstart bootloop bootroot boot
+
+  if grep -q console=null "$boot/cmdline.txt" ; then
+    info "/boot/cmdline.txt changed to temporarily enable console for autoexpand"
+    cp -p "$boot/cmdline.txt" "$boot/cmdline.txt.pishrink-bak"
+    sed -i "$boot/cmdline.txt" -e "$SEDCMDS"
+  else
+    # ok, already enabled. If a backup exists, it was done by us; check if the backup is stil valid.
+    if [ -f "$boot/cmdline.txt.pishrink-bak" ]; then
+      if [ "$(sed "$boot/cmdline.txt.pishrink-bak" -e "$SEDCMDS")" = "$(cat "$boot/cmdline.txt")" ]; then
+        info "/boot/cmdline.txt already changed to temporarily enable console for autoexpand"
+      else
+        # console was enabled by design - not by us. Remove backup to prevent installing it.
+        rm -f "$boot/cmdline.txt.pishrink-bak"
+      fi
+    fi
+  fi
+
+  [ -n "$bootroot" ] && umount "$bootroot"
+  [ -n "$bootloop" ] && losetup -d "$bootloop"
+}
+
 help() {
 	local help
 	read -r -d '' help << EOM

From 53ec477188c664b5ea4117953245b1e0eca7fa22 Mon Sep 17 00:00:00 2001
From: Lutz Schwarz <Lutz.Schwarz@vetrontypical.com>
Date: Thu, 3 Sep 2020 18:07:17 +0200
Subject: [PATCH 3/3] Fix detection of disabled console

---
 pishrink.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pishrink.sh b/pishrink.sh
index 3c70801..fbe88c7 100755
--- a/pishrink.sh
+++ b/pishrink.sh
@@ -189,7 +189,7 @@ function boot_enable_console () {
   local fsroot="$1"
   local bootstart="$(echo "$parted_output" | grep '^1:' | cut -d ':' -f 2 | tr -d 'B')"
   local boot bootloop bootroot
-  local SEDCMDS='s/console=null/console=tty0/'
+  local SEDCMDS='s/console=\(none\|null\)/console=tty0/'
 
   if [ -z "$fsroot" -o "x$bootstart" != "x$partstart" ]
   then
@@ -204,7 +204,7 @@ function boot_enable_console () {
 
   logVariables $LINENO fsroot bootstart bootloop bootroot boot
 
-  if grep -q console=null "$boot/cmdline.txt" ; then
+  if grep -q 'console=\(none\|null\)' "$boot/cmdline.txt" ; then
     info "/boot/cmdline.txt changed to temporarily enable console for autoexpand"
     cp -p "$boot/cmdline.txt" "$boot/cmdline.txt.pishrink-bak"
     sed -i "$boot/cmdline.txt" -e "$SEDCMDS"