Disable automatic workflow triggers; manual runs only

0.9.7.22: Originalmaße robust aus Nextcloud übernehmen

.github/workflows/lint.yml

@@ -1,8 +1,7 @@
 name: Syntax Check
 
 on:
-  push:
+  workflow_dispatch:
-  pull_request:
 
 jobs:
   php-syntax:

js/nc_connector_edit_v2.js

@@ -1,6 +1,134 @@
 (function () {
   'use strict';
 
+  var statusEndpoint = 'plugins/bratonien_tools/nc-connector-status.php';
+
+  function ensureLiveStatus(detail, actions) {
+    var node = detail.querySelector('[data-nc-run-live]');
+    if (node) return node;
+
+    node = document.createElement('div');
+    node.setAttribute('data-nc-run-live', '1');
+    node.className = 'bratonien-base-note';
+    node.style.marginTop = '.6rem';
+    node.hidden = true;
+    actions.parentNode.insertBefore(node, actions.nextSibling);
+    return node;
+  }
+
+  function renderLiveStatus(node, data) {
+    var state = String(data && data.state || '');
+    var message = String(data && data.message || '');
+    var detail = String(data && data.error_detail || '');
+
+    node.hidden = false;
+    node.innerHTML = '';
+
+    var strong = document.createElement('strong');
+    if (state === 'queued') strong.textContent = 'Angefordert: ';
+    else if (state === 'running') strong.textContent = 'Läuft: ';
+    else if (state === 'ok' || state === 'success') strong.textContent = 'Erfolgreich: ';
+    else if (state === 'error') strong.textContent = 'Fehler: ';
+    else strong.textContent = 'Status: ';
+    node.appendChild(strong);
+    node.appendChild(document.createTextNode(message || state || 'Status wird ermittelt …'));
+
+    if (detail) {
+      var details = document.createElement('details');
+      details.style.marginTop = '.35rem';
+      var summary = document.createElement('summary');
+      summary.textContent = 'Technische Laufzeitdetails';
+      var pre = document.createElement('pre');
+      pre.style.whiteSpace = 'pre-wrap';
+      pre.style.wordBreak = 'break-word';
+      pre.textContent = detail;
+      details.appendChild(summary);
+      details.appendChild(pre);
+      node.appendChild(details);
+    }
+  }
+
+  function pollConnection(connectionId, node, button) {
+    var attempts = 0;
+    var maxAttempts = 180;
+    var timer = null;
+
+    function stop() {
+      if (timer) window.clearInterval(timer);
+      timer = null;
+      if (button) {
+        button.disabled = false;
+        button.textContent = 'Jetzt abgleichen';
+      }
+    }
+
+    function poll() {
+      attempts += 1;
+      fetch(statusEndpoint + '?connection_id=' + encodeURIComponent(connectionId) + '&_=' + Date.now(), {
+        credentials: 'same-origin',
+        cache: 'no-store',
+        headers: {'Accept': 'application/json'}
+      })
+        .then(function (response) {
+          if (!response.ok) throw new Error('HTTP ' + response.status);
+          return response.json();
+        })
+        .then(function (data) {
+          renderLiveStatus(node, data);
+          var state = String(data && data.state || '');
+          if (state === 'ok' || state === 'success' || state === 'error' || attempts >= maxAttempts) stop();
+        })
+        .catch(function (error) {
+          if (attempts >= maxAttempts) {
+            renderLiveStatus(node, {state: 'error', message: 'Status konnte nicht gelesen werden.', error_detail: error.message});
+            stop();
+          }
+        });
+    }
+
+    poll();
+    timer = window.setInterval(poll, 1000);
+  }
+
+  function bindRunNow(form, detail, liveNode) {
+    if (form.dataset.ncRunBound === '1') return;
+    form.dataset.ncRunBound = '1';
+
+    form.addEventListener('submit', function (event) {
+      event.preventDefault();
+      detail.open = true;
+
+      var button = form.querySelector('button[value="nc_connector_run_now"]');
+      var connectionInput = form.querySelector('input[name="connection_id"]');
+      if (!connectionInput) return;
+
+      if (button) {
+        button.disabled = true;
+        button.textContent = 'Abgleich wird gestartet …';
+      }
+      renderLiveStatus(liveNode, {state: 'queued', message: 'Abgleich wird angefordert …'});
+
+      fetch(form.action || window.location.href, {
+        method: 'POST',
+        credentials: 'same-origin',
+        cache: 'no-store',
+        body: new FormData(form)
+      })
+        .then(function (response) {
+          if (!response.ok) throw new Error('HTTP ' + response.status);
+          renderLiveStatus(liveNode, {state: 'queued', message: 'Abgleich wurde angefordert.'});
+          pollConnection(connectionInput.value, liveNode, button);
+        })
+        .catch(function (error) {
+          renderLiveStatus(liveNode, {state: 'error', message: 'Abgleich konnte nicht angefordert werden.', error_detail: error.message});
+          if (button) {
+            button.disabled = false;
+            button.textContent = 'Jetzt abgleichen';
+          }
+        });
+    });
+  }
+
   function restoreRunNowButtons() {
     var section = document.getElementById('nc-connector');
     if (!section) return;
@@ -18,14 +146,17 @@
     var details = connectionCard.querySelectorAll(':scope > details');
     details.forEach(function (detail) {
       var actions = detail.querySelector('.bratonien-actions');
-      if (!actions || actions.querySelector('[value="nc_connector_run_now"]')) return;
+      if (!actions) return;
 
       var connectionInput = detail.querySelector('input[name="connection_id"]');
       var tokenInput = detail.querySelector('input[name="pwg_token"]');
       if (!connectionInput || !tokenInput) return;
 
-      var form = document.createElement('form');
+      var form = actions.querySelector('form[data-nc-run-now]');
+      if (!form) {
+        form = document.createElement('form');
         form.method = 'post';
+        form.setAttribute('data-nc-run-now', '1');
 
         var token = document.createElement('input');
         token.type = 'hidden';
@@ -48,6 +179,9 @@
         form.appendChild(button);
 
         actions.insertBefore(form, actions.firstChild);
+      }
+
+      bindRunNow(form, detail, ensureLiveStatus(detail, actions));
     });
   }
 

main.inc.php

@@ -1,7 +1,7 @@
 <?php
 /*
 Plugin Name: Bratonien Tools
-Version: 0.9.7.20
+Version: 0.9.7.23
 Description: Erweiterbare Administrationswerkzeuge fuer die Bratonien-Piwigo-Installation.
 Plugin URI: https://github.com/Terranom674/Piwigo_Bratonien_Tools
 Author: Bratonien

nc-connector-status.php

@@ -24,6 +24,7 @@ if (!function_exists('is_admin') || !is_admin())
   exit;
 }
 
+$requested_connection_id = isset($_GET['connection_id']) ? max(0, (int)$_GET['connection_id']) : 0;
 $dir = PHPWG_ROOT_PATH.'_data/bratonien-tools/nc-connector-status';
 $latest = array(
   'state'=>'idle',
@@ -41,11 +42,16 @@ $latest = array(
   'route_timestamp'=>0,
   'route_time_label'=>'Nicht verfügbar',
   'route_detail'=>'',
+  'connection_id'=>$requested_connection_id,
 );
 
 if (is_dir($dir))
 {
-  foreach (glob($dir.'/connection-*.json') ?: array() as $file)
+  $files = $requested_connection_id > 0
+    ? array($dir.'/connection-'.$requested_connection_id.'.json')
+    : (glob($dir.'/connection-*.json') ?: array());
+
+  foreach ($files as $file)
   {
     if (!is_readable($file))
     {
@@ -63,6 +69,8 @@ if (is_dir($dir))
     }
   }
 
+  if ($requested_connection_id === 0)
+  {
     $route_file = $dir.'/route-status.json';
     if (is_readable($route_file))
     {
@@ -111,10 +119,6 @@ if (is_dir($dir))
       }
     }
   }
-
-if ((int)$latest['timestamp'] > 0)
-{
-  $latest['last_run_label'] = date('d.m.Y H:i:s', (int)$latest['timestamp']);
 }
 
 $system_file = BRATONIEN_TOOLS_PATH.'include/nc_connector_system.inc.php';
@@ -129,4 +133,27 @@ if (is_readable($system_file))
   }
 }
 
+$scheduler_file = PHPWG_ROOT_PATH.'_data/bratonien-tools/nc-connector-scheduler/state.json';
+if ($requested_connection_id > 0 && is_readable($scheduler_file))
+{
+  $scheduler = json_decode((string)@file_get_contents($scheduler_file), true);
+  if (
+    is_array($scheduler)
+    && (int)($scheduler['connection_id'] ?? 0) === $requested_connection_id
+    && in_array((string)($scheduler['state'] ?? ''), array('queued','running'), true)
+    && (int)($scheduler['timestamp'] ?? 0) >= (int)($latest['timestamp'] ?? 0)
+  )
+  {
+    $latest['state'] = (string)$scheduler['state'];
+    $latest['message'] = (string)($scheduler['message'] ?? 'NC-Abgleich läuft.');
+    $latest['timestamp'] = (int)($scheduler['timestamp'] ?? time());
+    $latest['error_detail'] = '';
+  }
+}
+
+if ((int)$latest['timestamp'] > 0)
+{
+  $latest['last_run_label'] = date('d.m.Y H:i:s', (int)$latest['timestamp']);
+}
+
 echo json_encode($latest, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

runtime/lib/build_webdav_placeholder_source.py

@@ -2,8 +2,12 @@
 """Build a placeholder-backed local source tree from Nextcloud WebDAV.
 
 This creates only tiny placeholder files plus a metadata mapping; no Nextcloud
-original media is downloaded. The authenticated Nextcloud user is never used as
+original media is stored locally. The authenticated Nextcloud user is never used
-an album name.
+as an album name.
+
+Each placeholder carries the original image dimensions. Dimensions are read
+from Nextcloud metadata first. If those metadata are unavailable, only the
+beginning of the original file is read through WebDAV and parsed locally.
 """
 
 from __future__ import annotations
@@ -27,8 +31,10 @@ from pathlib import Path, PurePosixPath
 
 DAV = "DAV:"
 OC = "http://owncloud.org/ns"
+NC = "http://nextcloud.org/ns"
 SUPPORTED_IMAGE_EXTENSIONS = {".jpg", ".jpeg", ".png", ".gif", ".webp"}
 PLACEHOLDER = base64.b64decode("R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==")
+DIMENSION_PROBE_BYTES = 4 * 1024 * 1024
 
 
 def fail(message: str) -> None:
@@ -54,6 +60,101 @@ def safe_local_name(name: str) -> str:
     return name
 
 
+def parse_dimensions(prop: ET.Element) -> tuple[int, int]:
+    for property_name in ("file-metadata-size", "metadata-photos-size"):
+        raw = prop.findtext(f"{{{NC}}}{property_name}", default="").strip()
+        if not raw:
+            continue
+        try:
+            decoded = json.loads(raw)
+        except (TypeError, ValueError, json.JSONDecodeError):
+            continue
+        if isinstance(decoded, dict) and isinstance(decoded.get("value"), dict):
+            decoded = decoded["value"]
+        if not isinstance(decoded, dict):
+            continue
+        try:
+            width = int(decoded.get("width", 0) or 0)
+            height = int(decoded.get("height", 0) or 0)
+        except (TypeError, ValueError):
+            continue
+        if width > 0 and height > 0:
+            return width, height
+    return 0, 0
+
+
+def parse_image_header_dimensions(data: bytes) -> tuple[int, int]:
+    if len(data) >= 24 and data.startswith(b"\x89PNG\r\n\x1a\n") and data[12:16] == b"IHDR":
+        return int.from_bytes(data[16:20], "big"), int.from_bytes(data[20:24], "big")
+
+    if len(data) >= 10 and data[:6] in (b"GIF87a", b"GIF89a"):
+        return int.from_bytes(data[6:8], "little"), int.from_bytes(data[8:10], "little")
+
+    if len(data) >= 12 and data[:4] == b"RIFF" and data[8:12] == b"WEBP":
+        chunk = data[12:16]
+        if chunk == b"VP8X" and len(data) >= 30:
+            width = 1 + int.from_bytes(data[24:27], "little")
+            height = 1 + int.from_bytes(data[27:30], "little")
+            return width, height
+        if chunk == b"VP8 " and len(data) >= 30:
+            payload = 20
+            if data[payload + 3:payload + 6] == b"\x9d\x01\x2a":
+                width = int.from_bytes(data[payload + 6:payload + 8], "little") & 0x3FFF
+                height = int.from_bytes(data[payload + 8:payload + 10], "little") & 0x3FFF
+                return width, height
+        if chunk == b"VP8L" and len(data) >= 25 and data[20] == 0x2F:
+            b1, b2, b3, b4 = data[21:25]
+            width = 1 + b1 + ((b2 & 0x3F) << 8)
+            height = 1 + ((b2 & 0xC0) >> 6) + (b3 << 2) + ((b4 & 0x0F) << 10)
+            return width, height
+
+    if len(data) >= 4 and data[:2] == b"\xff\xd8":
+        sof_markers = {
+            0xC0, 0xC1, 0xC2, 0xC3,
+            0xC5, 0xC6, 0xC7,
+            0xC9, 0xCA, 0xCB,
+            0xCD, 0xCE, 0xCF,
+        }
+        pos = 2
+        while pos + 4 <= len(data):
+            if data[pos] != 0xFF:
+                pos += 1
+                continue
+            while pos < len(data) and data[pos] == 0xFF:
+                pos += 1
+            if pos >= len(data):
+                break
+            marker = data[pos]
+            pos += 1
+            if marker in (0xD8, 0xD9) or 0xD0 <= marker <= 0xD7:
+                continue
+            if marker == 0xDA:
+                break
+            if pos + 2 > len(data):
+                break
+            segment_length = int.from_bytes(data[pos:pos + 2], "big")
+            if segment_length < 2:
+                break
+            if marker in sof_markers:
+                if pos + 7 > len(data):
+                    break
+                height = int.from_bytes(data[pos + 3:pos + 5], "big")
+                width = int.from_bytes(data[pos + 5:pos + 7], "big")
+                return width, height
+            pos += segment_length
+
+    return 0, 0
+
+
+def placeholder_bytes(width: int, height: int) -> bytes:
+    if not (1 <= width <= 65535 and 1 <= height <= 65535):
+        fail(f"unsupported image dimensions for placeholder: {width}x{height}")
+    data = bytearray(PLACEHOLDER)
+    data[6:8] = width.to_bytes(2, "little")
+    data[8:10] = height.to_bytes(2, "little")
+    return bytes(data)
+
+
 @contextmanager
 def pinned_resolution(host: str, ip: str):
     host = host.strip("[]").lower()
@@ -92,22 +193,50 @@ class WebDavClient:
         self.auth_header = f"Basic {token}"
         self.context = ssl.create_default_context()
 
-    def collection_url(self, relative: str) -> str:
+    def file_url(self, relative: str) -> str:
         user = urllib.parse.quote(self.user, safe="")
         suffix = quote_path(relative)
-        url = f"{self.base_url}/remote.php/dav/files/{user}/"
+        return f"{self.base_url}/remote.php/dav/files/{user}/{suffix}"
-        if suffix:
+
-            url += suffix + "/"
+    def collection_url(self, relative: str) -> str:
+        url = self.file_url(relative)
+        if not url.endswith("/"):
+            url += "/"
         return url
 
+    def probe_dimensions(self, relative: str) -> tuple[int, int]:
+        request = urllib.request.Request(self.file_url(relative), method="GET")
+        request.add_header("Authorization", self.auth_header)
+        request.add_header("Range", f"bytes=0-{DIMENSION_PROBE_BYTES - 1}")
+        try:
+            with pinned_resolution(self.host, self.connect_ip):
+                with urllib.request.urlopen(request, timeout=self.timeout, context=self.context) as response:
+                    if response.status not in (200, 206):
+                        fail(f"Nextcloud image header returned HTTP {response.status}")
+                    data = response.read(DIMENSION_PROBE_BYTES)
+        except urllib.error.HTTPError as error:
+            if error.code in {401, 403}:
+                fail("Nextcloud rejected the WebDAV credentials or file access")
+            fail(f"Nextcloud image header request failed with HTTP {error.code}")
+        except urllib.error.URLError as error:
+            fail(f"Nextcloud WebDAV is unreachable while reading image dimensions: {error.reason}")
+
+        width, height = parse_image_header_dimensions(data)
+        if width < 1 or height < 1:
+            fail(f"original image dimensions could not be read from Nextcloud file header: {relative}")
+        return width, height
+
     def list_collection(self, relative: str) -> tuple[dict[str, object], list[dict[str, object]]]:
         relative = validate_relative(relative)
         url = self.collection_url(relative)
         body = (
             '<?xml version="1.0"?>'
-            '<d:propfind xmlns:d="DAV:" xmlns:oc="http://owncloud.org/ns">'
+            '<d:propfind xmlns:d="DAV:" xmlns:oc="http://owncloud.org/ns" '
+            'xmlns:nc="http://nextcloud.org/ns">'
             '<d:prop><d:displayname/><d:resourcetype/><d:getcontenttype/>'
-            '<d:getcontentlength/><d:getetag/><oc:fileid/></d:prop></d:propfind>'
+            '<d:getcontentlength/><d:getetag/><oc:fileid/>'
+            '<nc:file-metadata-size/><nc:metadata-photos-size/>'
+            '</d:prop></d:propfind>'
         ).encode("utf-8")
         request = urllib.request.Request(url, data=body, method="PROPFIND")
         request.add_header("Authorization", self.auth_header)
@@ -151,6 +280,7 @@ class WebDavClient:
             fileid_text = prop.findtext(f"{{{OC}}}fileid", default="").strip()
             resource_type = prop.find(f"{{{DAV}}}resourcetype")
             is_dir = resource_type is not None and resource_type.find(f"{{{DAV}}}collection") is not None
+            width, height = parse_dimensions(prop)
             item = {
                 "display_name": display,
                 "fileid": int(fileid_text) if fileid_text.isdigit() else 0,
@@ -158,6 +288,8 @@ class WebDavClient:
                 "content_type": prop.findtext(f"{{{DAV}}}getcontenttype", default=""),
                 "size": int(prop.findtext(f"{{{DAV}}}getcontentlength", default="0") or 0),
                 "etag": prop.findtext(f"{{{DAV}}}getetag", default="").strip('"'),
+                "width": width,
+                "height": height,
             }
             if href_path == base_path:
                 current = item
@@ -169,18 +301,17 @@ class WebDavClient:
         return current, children
 
 
-def link_placeholder(seed: Path, target: Path) -> None:
+def write_placeholder(target: Path, width: int, height: int) -> None:
     target.parent.mkdir(parents=True, exist_ok=True)
-    try:
+    target.write_bytes(placeholder_bytes(width, height))
-        os.link(seed, target)
+    os.chmod(target, 0o644)
-    except OSError:
-        target.write_bytes(PLACEHOLDER)
 
 
-def build_root(client: WebDavClient, remote_root: str, local_root: Path, seed: Path, mapping: dict[str, dict[str, object]]) -> tuple[int, int, int]:
+def build_root(client: WebDavClient, remote_root: str, local_root: Path, mapping: dict[str, dict[str, object]]) -> tuple[int, int, int, int]:
     files = 0
     folders = 0
     skipped = 0
+    probed = 0
     stack: list[tuple[str, Path]] = [(validate_relative(remote_root), local_root)]
     visited: set[str] = set()
 
@@ -210,7 +341,16 @@ def build_root(client: WebDavClient, remote_root: str, local_root: Path, seed: P
             if extension not in SUPPORTED_IMAGE_EXTENSIONS:
                 skipped += 1
                 continue
-            link_placeholder(seed, child_local)
+
+            width = int(child.get("width", 0) or 0)
+            height = int(child.get("height", 0) or 0)
+            dimension_source = "metadata"
+            if width < 1 or height < 1:
+                width, height = client.probe_dimensions(child_remote)
+                dimension_source = "header"
+                probed += 1
+
+            write_placeholder(child_local, width, height)
             files += 1
             mapping[str(child_local)] = {
                 "kind": "file",
@@ -220,8 +360,11 @@ def build_root(client: WebDavClient, remote_root: str, local_root: Path, seed: P
                 "content_type": str(child.get("content_type", "")),
                 "size": int(child.get("size", 0)),
                 "etag": str(child.get("etag", "")),
+                "width": width,
+                "height": height,
+                "dimension_source": dimension_source,
             }
-    return files, folders, skipped
+    return files, folders, skipped, probed
 
 
 def atomic_json(path: Path, payload: object) -> None:
@@ -265,10 +408,7 @@ def main() -> int:
         source_dir = args.source_dir.resolve()
         staging = source_dir.with_name(f".{source_dir.name}.next")
         previous = source_dir.with_name(f".{source_dir.name}.previous")
-        seed = source_dir.parent / ".bratonien-webdav-placeholder.gif"
         source_dir.parent.mkdir(parents=True, exist_ok=True)
-        seed.write_bytes(PLACEHOLDER)
-        os.chmod(seed, 0o644)
         if staging.exists():
             shutil.rmtree(staging)
         staging.mkdir(parents=True)
@@ -276,7 +416,7 @@ def main() -> int:
         client = WebDavClient(args.base_url, args.user, password, max(1, args.timeout), args.connect_ip)
         mapping: dict[str, dict[str, object]] = {}
         manifest: list[str] = []
-        total_files = total_folders = total_skipped = 0
+        total_files = total_folders = total_skipped = total_probed = 0
         used_fileids: set[int] = set()
 
         for remote_root_raw in args.root:
@@ -288,10 +428,11 @@ def main() -> int:
             used_fileids.add(fileid)
             local_name = f"root-{fileid}"
             local_root = staging / local_name
-            files, folders, skipped = build_root(client, remote_root, local_root, seed, mapping)
+            files, folders, skipped, probed = build_root(client, remote_root, local_root, mapping)
             total_files += files
             total_folders += folders
             total_skipped += skipped
+            total_probed += probed
 
             if remote_root == "":
                 for child in sorted(root_children, key=lambda item: str(item.get("display_name", "")).casefold()):
@@ -333,7 +474,7 @@ def main() -> int:
 
         atomic_text(args.manifest, "\n".join(manifest) + "\n")
         atomic_json(args.mapping, {
-            "version": 1,
+            "version": 3,
             "base_url": args.base_url.rstrip("/"),
             "connect_ip": client.connect_ip,
             "user": args.user,
@@ -344,6 +485,7 @@ def main() -> int:
             "files": total_files,
             "folders": total_folders,
             "skipped": total_skipped,
+            "dimension_header_probes": total_probed,
             "connect_ip": client.connect_ip,
             "source_dir": str(source_dir),
             "manifest": str(args.manifest),

runtime/sync-webdav.sh

@@ -78,7 +78,9 @@ done < "$WEBDAV_ROOTS_FILE"
 WEBDAV_CONNECT_IP="$(php "$SCRIPT_DIR/lib/resolve-nextcloud-target.php" "$WEBDAV_BASE_URL")"
 [[ -n "$WEBDAV_CONNECT_IP" ]] || { write_status error "Nextcloud-Zieladresse konnte nicht ermittelt werden"; exit 1; }
 
-python3 "$SCRIPT_DIR/lib/build_webdav_placeholder_source.py" \
+PLACEHOLDER_OUTPUT=""
+PLACEHOLDER_EXIT=0
+if PLACEHOLDER_OUTPUT="$(python3 "$SCRIPT_DIR/lib/build_webdav_placeholder_source.py" \
     --base-url "$WEBDAV_BASE_URL" \
     --connect-ip "$WEBDAV_CONNECT_IP" \
     --user "$WEBDAV_USER" \
@@ -86,12 +88,42 @@ python3 "$SCRIPT_DIR/lib/build_webdav_placeholder_source.py" \
     "${ROOT_ARGS[@]}" \
     --source-dir "$WEBDAV_SOURCE_DIR" \
     --manifest "$MANIFEST" \
-    --mapping "$WEBDAV_MAPPING_FILE"
+    --mapping "$WEBDAV_MAPPING_FILE" 2>&1)"; then
+    PLACEHOLDER_EXIT=0
+else
+    PLACEHOLDER_EXIT=$?
+fi
+[[ -z "$PLACEHOLDER_OUTPUT" ]] || printf '%s\n' "$PLACEHOLDER_OUTPUT"
+if [[ "$PLACEHOLDER_EXIT" -ne 0 ]]; then
+    DETAIL="Exit-Code: $PLACEHOLDER_EXIT"
+    if [[ -n "$PLACEHOLDER_OUTPUT" ]]; then
+        DETAIL+="; Ausgabe: $(printf '%s\n' "$PLACEHOLDER_OUTPUT" | tail -n 20 | tr '\n' ' ' | sed 's/[[:space:]]\+/ /g; s/^[[:space:]]//; s/[[:space:]]$//')"
+    fi
+    trap - ERR
+    write_status error "WebDAV-Shadow-Tree fehlgeschlagen" "$DETAIL"
+    exit "$PLACEHOLDER_EXIT"
+fi
 
-python3 "$SCRIPT_DIR/lib/shadow_tree.py" \
+SHADOW_OUTPUT=""
+SHADOW_EXIT=0
+if SHADOW_OUTPUT="$(python3 "$SCRIPT_DIR/lib/shadow_tree.py" \
     --manifest "$MANIFEST" \
     --destination "$GALLERY_ROOT" \
-    --state "$SHADOW_MAP_FILE"
+    --state "$SHADOW_MAP_FILE" 2>&1)"; then
+    SHADOW_EXIT=0
+else
+    SHADOW_EXIT=$?
+fi
+[[ -z "$SHADOW_OUTPUT" ]] || printf '%s\n' "$SHADOW_OUTPUT"
+if [[ "$SHADOW_EXIT" -ne 0 ]]; then
+    DETAIL="Exit-Code: $SHADOW_EXIT"
+    if [[ -n "$SHADOW_OUTPUT" ]]; then
+        DETAIL+="; Ausgabe: $(printf '%s\n' "$SHADOW_OUTPUT" | tail -n 20 | tr '\n' ' ' | sed 's/[[:space:]]\+/ /g; s/^[[:space:]]//; s/[[:space:]]$//')"
+    fi
+    trap - ERR
+    write_status error "WebDAV-Shadow-Tree fehlgeschlagen" "$DETAIL"
+    exit "$SHADOW_EXIT"
+fi
 
 trap - ERR