'git pull' calls the hook post-merge when new data arrive.

If this is the case, write a file /tmp/git-pull which contains the names
of changed files.
Do not search for any special output of git.

git_helpers

@@ -83,14 +83,26 @@ clone_customer_repository () {
                 $(exec_git_command git clone "$1")
                 if [ $? -eq 0 ]; then
                     log_debug "$func:${LINENO} cloning ${1} done"
-                    local res=$(exec_git_command git --git-dir="${CUSTOMER_ID_BASE_DIR}/.git" --work-tree="/" init)
-                    if ! [[ -z $res ]]; then
-                        CLONE_CUSTOMER_REPOSITORY=true
-                        log_debug "$func:${LINENO} re-init of ${1} done"
-                        cd -; return 0
+                    # after cloning, cd into repository, and re-initialize,
+                    # setting the work-tree as "/". This has the effect that
+                    # a "git pull" will automatically fetched files in the
+                    # corresponding sytem-folders.
+                    if cd ${CUSTOMER_ID_BASE_DIR}; then
+                        local res=$(exec_git_command git --git-dir=.git --work-tree=/ init)
+                        if ! [[ -z $res ]]; then
+                            # re-initialized. copy post-merge (a hook called
+                            # when 'git pull' is executed and changed data
+                            # are received).
+                            if cp ".githooks/post-merge" ".git/hooks"; then
+                                log_debug "$func:${LINENO} copied post-merge to .git/hooks"
+                                CLONE_CUSTOMER_REPOSITORY=true
+                                log_debug "$func:${LINENO} re-init of ${1} done"
+                                cd_home; return 0
+                            fi
+                        fi
                     fi
                 fi
-                cd -
+                cd_home; return 1
             fi
         else
             # the directory is not empty, so we assume the
@@ -148,109 +160,27 @@ pull_customer_repository () {
         return 1
     fi
 
-    local commit_before_pull=$(latest_commit)
-    if [ -z $commit_before_pull ]; then
-        log_warn "$func:${LINENO}: commit_before_pull empty"
-        cd_home ; return 1
-    fi
-    log_debug "$func:${LINENO}: commit_before_pull=$commit_before_pull"
+    #local commit_before_pull=$(latest_commit)
+    #if [ -z $commit_before_pull ]; then
+    #    log_warn "$func:${LINENO}: commit_before_pull empty"
+    #    cd_home ; return 1
+    #fi
+    #log_debug "$func:${LINENO}: commit_before_pull=$commit_before_pull"
+
+    rm -f "$OPKG_CMDS_TMP"
+    rm -f "$GIT_PULL_TMP"
+
     log_debug "$func:${LINENO}: executing 'git pull'..."
-   
-    local git_result=$(exec_git_command 'git pull')
+    exec_git_command 'git pull'
 
-    if [ -z "$git_result" ]; then
-        log_warn "$func:${LINENO}: git result empty" ; cd_home;
-        return 1
+    # GIT_PULL_TMP created by hook post-merge. it contains the names of the
+    # changed files.
+    if [[ -f $GIT_PULL_TMP ]]; then
+        cd_home; return 0
     fi
 
-    # see https://www.gnu.org/
-    #           software/bash/manual/html_node/Shell-Parameter-Expansion.html
-    # [...]
-    #   
-    #    ${parameter//pattern/string}
-    #
-    # If there are two slashes separating parameter and pattern (...),
-    # all matches of pattern are replaced with string.
-    # 
-    # If the expansion of string is null, matches of pattern are deleted.
-    # [...]
-    git_result=${git_result//[$'\r\n\t']/ }
-
-    log_debug "$func:${LINENO} git-pull-result=${git_result}"
-
-    if grep -qE "^.*?Already\s+\up\s+\to\s+date.*$" <<< "$git_result"; then
-        log_warn "$func:${LINENO}: repository $PWD already up to date."
-        read $1 <<< 'yes'
-        cd_home ; return 1
-    fi
-
-    local commit_after_pull=$(latest_commit)
-    if [ -z $commit_after_pull ]; then
-        cd_home ; return 1
-    fi
-    
-    log_debug "$func:${LINENO}: commit_after_pull=$commit_after_pull"
-
-    # Note: # 'git pull' is a 'git fetch' followed by a 'git merge'.
-    # Here's the fetch portion:
-    #
-    # remote: Counting objects: 11, done.
-    # remote: Compressing objects: 100% (5/5), done.
-    # remote: Total 7 (delta 2), reused 0 (delta 0)
-    #
-    # At this point, you've told the remote what you want.
-    # It finds all the objects it needs to give you,
-    # compresses them for faster transfer over the network,
-    # and then reports what it's sending you.
-    # 
-    # Unpacking objects: 100% (7/7), done.
-    # 
-    # You receive the pack (set of compressed objects) and unpack it.
-    #
-    # From ssh://my.remote.host.com/~/git/myproject
-    # * branch            master     -> FETCH_HEAD
-
-    # You've fetched the branch 'master' from the given remote;
-    # the ref FETCH_HEAD now points to it.
-    # Now we move on to the merge - precisely, git will merge
-    # FETCH_HEAD (the remote's master branch) into your current branch
-    # (presumably master).
-    #
-    #######################################################################
-    # here starts "message"
-    # 
-    # Updating 9d447d2..f74fb21
-    # Fast forward
-    #
-    # It turns out that you haven't diverged from the remote's master branch,
-    # so the merge is a fast-forward (a trivial merge where it simply moves
-    # you forward in the history).
-    #
-    # Git notes the original position of your master branch (9d447d2)
-    # and the new position (f74fb21) it's been fast-forwarded to.
-    # If you had diverged from the remote's master branch,
-    # you'd see the output of a recursive merge here - Merge made
-    # by recursive, possibly along with some Auto-merged <file>
-    # and (oh no!) merge conflicts!
-    #
-    # szeged/1/1/etc/psa_config/device.conf | 13 +++++++------
-    # szeged/update.conf                    |  2 +-
-    # 2 files changed, 8 insertions(+), 7 deletions(-)
-    #  
-    # Finally, it shows you the diffstat between the original and post-merge
-    # position of your master branch;
-    # this is basically what you'd get from
-    #
-    # git diff --stat master@{1} master.
-    # 
-
-    update_commit="${commit_before_pull}..${commit_after_pull}"
-    if ! grep -qE ".*Updating\s+${update_commit}.*?" <<< $git_result; then
-        log_crit "$func:${LINENO}: no $update_commit in [ $git_result ]"
-        cd_home ; return 1
-    fi
-
-    cd_home ; return 0
+    log_warn "$func:${LINENO}: no data fetched form repository"
+    cd_home; return 1
 }
 # pull_customer_repository customer_281
 

update_psa_helpers

@@ -24,7 +24,7 @@ exec_opkg_command () {
 # Fetch/merge updates from predefined repository using git.
 # 
 fetch_customer_updates() {
-    if ! pull_customer_repository $1; then
+    if ! pull_customer_repository; then
         return 1
     fi
     return 0

update_psa_impl

@@ -35,42 +35,20 @@ update_psa() {
         exit $?
     fi
 
-    rm -f "$OPKG_CMDS_TMP"
-    rm -f "$GIT_PULL_TMP"
-
     update_psa_activated    # message to ISMAS
             
-    local try_update_count=0
     local func="${FUNCNAME[0]}"
 
     log_debug "$func:${LINENO}: fetch/merge updates..."
    
     # Fetch new updates (using git)
-    while :
-    do
-        local repository_is_already_up_to_date=""
-        if ! fetch_customer_updates repository_is_already_up_to_date; then
-            if [ "$repository_is_already_up_to_date" = "yes" ]; then
-                log_error "$func:${LINENO}: $customer_id is up-to-date"\
-                    "-> no files to update -> no psa update"
-                update_psa_false_alarm \
-                    "update request, but no change in $CUSTOMER_REPOSITORY_PATH"
-                exit $?
-            fi
-            try_updates_count=$((try_updates_count+1))
-            if [[ "$try_updates_count" -eq 5 ]]; then
-                log_error "$func:${LINENO}: fetch/merging failed"
-                update_psa_pull_error # message to ISMAS
-                exit $?
-            fi
-            update_psa_pull_error # message to ISMAS
-            sleep 10s
-        else
-            # Fetched updates successfully 
-            try_updates_count=0
-            break
-        fi
-    done
+    if ! fetch_customer_updates; then
+        log_error "$func:${LINENO}: fetch no data for $customer_id"\
+            "-> no files to update -> no psa update"
+        update_psa_false_alarm \
+            "update request, but no change in $CUSTOMER_REPOSITORY_PATH"
+        # TODO
+    fi
             
     update_psa_pull_customer_repository # message to ISMAS
 
@@ -78,7 +56,7 @@ update_psa() {
     
     # local changed_files=$(changed_file_names)
    
-    if [[ ! -z $GIT_PULL_TMP ]]; then 
+    if [[ -f "$GIT_PULL_TMP" ]]; then 
         # TODO
         if ! check_hardware_compatibility "$files_to_copy" ; then
             local __r=$?
@@ -88,7 +66,7 @@ update_psa() {
         fi
     fi
 
-    if [[ ! -z "$OPKG_CMDS_TMP" ]]; then
+    if [[ -f "$OPKG_CMDS_TMP" ]]; then
         local commands="$(cat ${OPKG_CMDS_TMP} | tr '\n' '; ')"
         log_info "$func:${LINENO}: executed opkg commands"
         update_psa_install_opkg_packages $UPDATE_ISMAS_PROGRESS \
@@ -158,6 +136,7 @@ update_psa() {
     update_psa_cleanup $UPDATE_ISMAS_PROGRESS \
         $RC_SUCCESS "cleanup after psa update"
 
+    # TODO
     exit 0
 }