fix(appimage): cd "$APPDIR" in AppRun before exec to fix sharun preload CWD resolution (#2829)

Co-authored-by: Taimoor <astikkosapparel009@gmail.com>
Co-authored-by: sanil-23 <sanil@vezures.xyz>

scripts/release/strip-appimage-graphics-libs.sh

@@ -363,6 +363,80 @@ validate_sharun_lib_path() {
   fi
 }
 
+# patch_apprun_sharun_cwd — inject `cd "$APPDIR"` into AppRun before the final
+# exec call so sharun resolves preload/library paths relative to the AppDir
+# rather than the caller's CWD.
+#
+# Problem (issue #2822): sharun reads its `.preload` entry and library search
+# paths relative to the process CWD.  When a user launches the AppImage from
+# any directory other than the AppDir itself (e.g. double-click from ~/Downloads)
+# CWD != AppDir, so ld.so can't find `anylinux.so` (preload) or `libcef.so`
+# (LD_LIBRARY_PATH entry).  SHARUN_DIR is set correctly — the AppDir IS known —
+# but sharun doesn't use it to anchor the preload/library arguments it hands to
+# ld.so.
+#
+# Fix: prepend `cd "$APPDIR"` to the exec line in AppRun so the working
+# directory is always the AppDir by the time sharun/the binary runs.  This
+# mirrors the verified manual workaround from the bug report.
+#
+# Returns 0 (true) if the AppRun was modified, 1 if no change was needed.
+patch_apprun_sharun_cwd() {
+  local appdir="$1"
+  if ! uses_sharun_launcher "$appdir"; then
+    return 1
+  fi
+
+  local apprun="$appdir/AppRun"
+  if [ ! -f "$apprun" ]; then
+    # Some sharun bundles use the sharun binary directly as the AppDir entry
+    # point without a separate shell AppRun.  Nothing to patch in that case.
+    return 1
+  fi
+
+  # Check if the file is a shell script (not an ELF binary).
+  local first_bytes
+  first_bytes="$(LC_ALL=C head -c 2 "$apprun" 2>/dev/null || true)"
+  if [ "$first_bytes" = $'\x7fE' ]; then
+    # AppRun is an ELF binary — cannot patch with sed.
+    return 1
+  fi
+
+  # Idempotency guard: skip if we already patched this AppRun.
+  # Match only the exact patched line — a loose substring (e.g. 'cd.*"$APPDIR"')
+  # would false-positive on comments like '# cd "$APPDIR"' or unrelated lines
+  # and leave the real `exec "$@"` unpatched.
+  local patched_line_re='^[[:space:]]*cd[[:space:]]+"\$APPDIR"[[:space:]]*&&[[:space:]]*exec[[:space:]]+"\$@"[[:space:]]*$'
+  if grep -Eq "$patched_line_re" "$apprun" 2>/dev/null; then
+    return 1
+  fi
+
+  # Locate the exec line.  AppRun scripts generated by lib4bin / sharun
+  # typically have a line of the form (possibly with leading whitespace):
+  #   exec "$@"
+  # Patch it to:
+  #   cd "$APPDIR" && exec "$@"
+  #
+  # The sed pattern is anchored to end-of-line ($) so trailing content (extra
+  # args, comments, redirections) doesn't get silently absorbed into the cd &&
+  # exec sequence.
+  #
+  # Use a temp file + mv to avoid truncating AppRun mid-write on failure.
+  local tmp_apprun
+  tmp_apprun="$(mktemp)"
+  if sed 's|^\([[:space:]]*\)exec "\$@"[[:space:]]*$|\1cd "$APPDIR" \&\& exec "$@"|' \
+       "$apprun" > "$tmp_apprun" \
+     && grep -Eq "$patched_line_re" "$tmp_apprun"; then
+    chmod --reference="$apprun" "$tmp_apprun"
+    mv "$tmp_apprun" "$apprun"
+    echo "[strip-libs]   patched AppRun: added 'cd \"\$APPDIR\"' before exec to fix sharun CWD preload resolution (issue #2822)"
+    return 0
+  else
+    rm -f "$tmp_apprun"
+    echo "[strip-libs] WARNING: could not locate 'exec \"\$@\"' in AppRun — sharun CWD fix not applied; AppImage may fail to launch from non-AppDir CWDs" >&2
+    return 1
+  fi
+}
+
 strip_one_appimage() {
   local img="$1"
   local original
@@ -386,6 +460,7 @@ strip_one_appimage() {
   local removed=0
   local added_loader=0
   local rewrote_libpath=0
+  local patched_apprun=0
   local lib_roots=()
   for candidate in \
     "$appdir/usr/lib" \
@@ -420,14 +495,17 @@ strip_one_appimage() {
   if rewrite_sharun_lib_path "$appdir"; then
     rewrote_libpath=1
   fi
+  if patch_apprun_sharun_cwd "$appdir"; then
+    patched_apprun=1
+  fi
   validate_sharun_lib_path "$appdir"
 
-  if [ "$removed" -eq 0 ] && [ "$added_loader" -eq 0 ] && [ "$rewrote_libpath" -eq 0 ]; then
+  if [ "$removed" -eq 0 ] && [ "$added_loader" -eq 0 ] && [ "$rewrote_libpath" -eq 0 ] && [ "$patched_apprun" -eq 0 ]; then
     echo "[strip-libs] No graphics libs or missing sharun interpreter found in $original; leaving unchanged."
     rm -rf "$workdir"
     return
   fi
-  echo "[strip-libs] Removed $removed file(s), added $added_loader loader file(s); repacking AppImage."
+  echo "[strip-libs] Removed $removed file(s), added $added_loader loader file(s), patched AppRun=$patched_apprun; repacking AppImage."
 
   local rebuilt="$workdir/$name"
   local appimage_arch