Don't use git tags in pull

As seen in #225, this approach was more complicated
than it needed to be and caused confusion for users.

bin/homeshick

@@ -171,6 +171,7 @@ case $cmd in
   cd)    help cd        ;; # cd is implemented in the homeshick.{sh,csh} helper script.
   help)  help $help_cmd ;;
   *)
+    declare -a pull_completed
     for param in "${params[@]}"; do
       case $cmd in
         clone)
@@ -182,7 +183,13 @@ case $cmd in
         refresh)
           (refresh $threshhold "$param") ;;
         pull)
-          (pull "$param") && pull_completed+=("$param") ;;
+          prev_hash=$(cd "$repos/$param" && git rev-parse HEAD)
+          (pull "$param")
+          result=$?
+          curr_hash=$(cd "$repos/$param" && git rev-parse HEAD)
+          [[ "$prev_hash" != "$curr_hash" ]] && pull_completed+=("$param")
+          (exit $result)
+          ;;
         symlink|link)
           symlink "$param" ;;
         track)

lib/commands/pull.sh

@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 
-BEFORE_PULL_TAG=__homeshick-before-pull__
 pull() {
   [[ ! $1 ]] && help_err pull
   local castle=$1
@@ -14,15 +13,6 @@ pull() {
     return "$EX_SUCCESS"
   fi
 
-  # this tag is exceedingly unlikely to already exist, but if it does, error
-  # out and let the user resolve it
-  (cd "$repo" && git rev-parse --verify "refs/tags/$BEFORE_PULL_TAG" &>/dev/null) && \
-    err "$EX_DATAERR" "Pull marker tag ($BEFORE_PULL_TAG) already exists in $repo. Please resolve this before pulling."
-  # make a tag at the current commit, so we can compare against it below
-  (cd "$repo" && git tag --no-sign "$BEFORE_PULL_TAG" 2>&1)
-  # remove the tag if one of the git operations fails
-  trap 'cd "$repo" && git tag -d "$BEFORE_PULL_TAG" &>/dev/null' EXIT
-
   local git_out
   git_out=$(cd "$repo" && git pull 2>&1) || \
     err "$EX_SOFTWARE" "Unable to pull $repo. Git says:" "$git_out"
@@ -36,7 +26,6 @@ pull() {
       err "$EX_SOFTWARE" "Unable update submodules for $repo. Git says:" "$git_out"
   fi
   success
-  trap - EXIT
   return "$EX_SUCCESS"
 }
 
@@ -46,17 +35,14 @@ symlink_new_files() {
     local castle=$1
     shift
     local repo="$repos/$castle"
-    local git_out
-    git_out=$(cd "$repo" && git diff --name-only --diff-filter=AR "$BEFORE_PULL_TAG" HEAD -- home 2>/dev/null | wc -l 2>&1)
-    local result=$?
-    # Remove the tag before doing anything else
-    (cd "$repo" && git tag -d "$BEFORE_PULL_TAG" &>/dev/null)
-    if [[ $result -ne 0 ]]; then
-      continue  # Ignore errors, this operation is not mission critical
-    fi
     if [[ ! -d $repo/home ]]; then
       continue;
     fi
+    # @{1} refers to the previous reflog entry on the current branch, which
+    # will be right before the pull
+    if ! git_out=$(cd "$repo" && git diff --name-only --diff-filter=AR '@{1}' HEAD -- home 2>/dev/null | wc -l 2>&1); then
+      continue  # Ignore errors, this operation is not mission critical
+    fi
     if [[ $git_out -gt 0 ]]; then
       updated_castles+=("$castle")
     fi