From 4f1eec818029df209ef275752cff36d6dfbb1c16 Mon Sep 17 00:00:00 2001
From: Robert Helgesson <robert@rycee.net>
Date: Wed, 29 Mar 2017 00:10:30 +0200
Subject: [PATCH] Avoid undefined variables in activation script

---
 modules/activation-init.sh   | 11 ++++++++---
 modules/home-environment.nix |  4 ++--
 modules/systemd.nix          | 10 +++++++---
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/modules/activation-init.sh b/modules/activation-init.sh
index 5ac5fdfe2..a7011b9c2 100755
--- a/modules/activation-init.sh
+++ b/modules/activation-init.sh
@@ -47,10 +47,15 @@ else
 fi
 
 $VERBOSE_ECHO "Activation variables:"
-$VERBOSE_ECHO "  oldGenNum=$oldGenNum"
-$VERBOSE_ECHO "  newGenNum=$newGenNum"
-$VERBOSE_ECHO "  oldGenPath=$oldGenPath"
+if [[ -v oldGenNum ]] ; then
+    $VERBOSE_ECHO "  oldGenNum=$oldGenNum"
+    $VERBOSE_ECHO "  oldGenPath=$oldGenPath"
+else
+    $VERBOSE_ECHO "  oldGenNum undefined (first run?)"
+    $VERBOSE_ECHO "  oldGenPath undefined (first run?)"
+fi
 $VERBOSE_ECHO "  newGenPath=$newGenPath"
+$VERBOSE_ECHO "  newGenNum=$newGenNum"
 $VERBOSE_ECHO "  newGenProfilePath=$newGenProfilePath"
 $VERBOSE_ECHO "  newGenGcPath=$newGenGcPath"
 $VERBOSE_ECHO "  genProfilePath=$genProfilePath"
diff --git a/modules/home-environment.nix b/modules/home-environment.nix
index cef70541a..8c3c462e9 100644
--- a/modules/home-environment.nix
+++ b/modules/home-environment.nix
@@ -281,7 +281,7 @@ in
           }
 
           function cleanOldGen() {
-            if [[ -z "$oldGenPath" ]] ; then
+            if [[ ! -v oldGenPath ]] ; then
               return
             fi
 
@@ -294,7 +294,7 @@ in
               | xargs -0 bash ${cleanup} "$newGenFiles" "$oldGenFiles"
           }
 
-          if [[ "$oldGenPath" != "$newGenPath" ]] ; then
+          if [[ ! -v oldGenPath || "$oldGenPath" != "$newGenPath" ]] ; then
             $DRY_RUN_CMD ln -Tsf $VERBOSE_ARG "$newGenPath" "$newGenProfilePath"
             $DRY_RUN_CMD ln -Tsf $VERBOSE_ARG "$newGenProfilePath" "$genProfilePath"
             $DRY_RUN_CMD ln -Tsf $VERBOSE_ARG "$newGenPath" "$newGenGcPath"
diff --git a/modules/systemd.nix b/modules/systemd.nix
index 57c819e01..293b32df1 100644
--- a/modules/systemd.nix
+++ b/modules/systemd.nix
@@ -74,17 +74,21 @@ in
         local workDir
         workDir="$(mktemp -d)"
 
-        local oldUserServicePath="$oldGenPath/home-files/.config/systemd/user"
+        if [[ -v oldGenPath ]] ; then
+          local oldUserServicePath="$oldGenPath/home-files/.config/systemd/user"
+        fi
+
         local newUserServicePath="$newGenPath/home-files/.config/systemd/user"
         local oldServiceFiles="$workDir/old-files"
         local newServiceFiles="$workDir/new-files"
         local servicesDiffFile="$workDir/diff-files"
 
-        if [[ ! -d "$oldUserServicePath" && ! -d "$newUserServicePath" ]]; then
+        if [[ ! (-v oldUserServicePath && -d "$oldUserServicePath") \
+            && ! -d "$newUserServicePath" ]]; then
           return
         fi
 
-        if [[ ! -d "$oldUserServicePath" ]]; then
+        if [[ ! (-v oldUserServicePath && -d "$oldUserServicePath") ]]; then
           touch "$oldServiceFiles"
         else
           find "$oldUserServicePath" \