feat: Improve error handling (#2120)

src/answer.sh

@@ -30,10 +30,21 @@ updateXML() {
   [ -z "${HEIGHT:-}" ] && HEIGHT="720"
 
   validateXMLSettings || return 1
-  ensureXMLDefaultNamespace "$asset" || return 1
 
-  updateUserXML "$asset" || return 1
-  updateLocaleXML "$asset" "$language" || return 1
+  if ! ensureXMLDefaultNamespace "$asset"; then
+    error "Failed to prepare the answer file XML namespace!"
+    return 1
+  fi
+
+  if ! updateUserXML "$asset"; then
+    error "Failed to update user and display settings in answer file!"
+    return 1
+  fi
+
+  if ! updateLocaleXML "$asset" "$language"; then
+    error "Failed to update regional settings in answer file!"
+    return 1
+  fi
 
   if [ -n "$domain" ]; then
 
@@ -46,13 +57,24 @@ updateXML() {
 
   else
 
-    updateLocalAccount "$asset" || return 1
+    if ! updateLocalAccount "$asset"; then
+      error "Failed to update local account settings in answer file!"
+      return 1
+    fi
 
   fi
 
   updateMembership "$asset" "$domain" "$workgroup" "$account" "$auth" || return 1
-  updateAutologinXML "$asset" || return 1
-  updateEditionXML "$asset" || return 1
+
+  if ! updateAutologinXML "$asset"; then
+    error "Failed to update automatic logon settings in answer file!"
+    return 1
+  fi
+
+  if ! updateEditionXML "$asset"; then
+    error "Failed to update edition settings in answer file!"
+    return 1
+  fi
 
   validateGeneratedXML "$asset" || return 1
 
@@ -73,7 +95,7 @@ setXML() {
 
   if [ -d "${custom_files[0]}" ]; then
     error "The bind ${custom_files[0]} maps to a file that does not exist!"
-    exit 67
+    return 2
   fi
 
   # A custom answer file always takes precedence over bundled or generated
@@ -182,7 +204,7 @@ addAnswerFile() {
 
   if ! updateDiskID "$answer" "${DISK_TYPE:-}"; then
     error "Failed to adjust the Windows installation disk!"
-    exit 85
+    return 1
   fi
 
   if ! setConfigurationXML "$answer"; then
@@ -194,7 +216,10 @@ addAnswerFile() {
 
   if [ -z "${CUSTOM_XML:-}" ]; then
 
-    prepareSetupScript "$asset" "$stage" || exit 84
+    if ! prepareSetupScript "$asset" "$stage"; then
+      error "Failed to prepare the Windows setup script!"
+      return 1
+    fi
 
   fi
 
@@ -1080,7 +1105,13 @@ updateDiskID() {
 
   done <<< "$values"
 
-  mapfile -t ids < <(printf '%s\n' "${ids[@]}" | sort -u)
+  local unique
+  unique=$(printf '%s\n' "${ids[@]}" | sort -u) || {
+    error "Failed to normalize DiskID values from answer file: $asset"
+    return 1
+  }
+
+  mapfile -t ids <<< "$unique"
 
   # Leave explicit multi-disk configurations untouched.
   (( ${#ids[@]} == 1 )) || return 0
@@ -1946,10 +1977,16 @@ markGeneratedXML() {
 
   local file="$1"
   local marker='<!-- generated-answer-file: do not reuse as a template -->'
+  local first
 
   [ -s "$file" ] || return 1
 
-  if head -n 1 "$file" | grep -q '^<?xml'; then
+  if ! first=$(head -n 1 "$file"); then
+    error "Failed to inspect generated answer file: $file"
+    return 1
+  fi
+
+  if [[ "$first" == "<?xml"* ]]; then
     sed -i "1a$marker" "$file" || return 1
   else
     sed -i "1i$marker" "$file" || return 1
@@ -1961,12 +1998,17 @@ markGeneratedXML() {
 removeGeneratedXML() {
 
   local file="$1"
+  local header
 
   [ -n "$file" ] || return 0
   [ -f "$file" ] || return 0
 
-  head -n 5 "$file" |
-    grep -Fqi 'generated-answer-file' || return 0
+  if ! header=$(head -n 5 "$file"); then
+    error "Failed to inspect answer file: $file"
+    return 1
+  fi
+
+  grep -Fqi 'generated-answer-file' <<< "$header" || return 0
 
   if ! rm -f "$file"; then
     error "Failed to remove generated answer file: $file"
@@ -2323,10 +2365,18 @@ addSIFEntry() {
     return 1
   fi
 
-  if grep -Fqx "$entry" "$file" || grep -Fqx "$entry"$'\r' "$file"; then
+  local rc=0
+  grep -Fqx -e "$entry" -e "$entry"$'\r' "$file" || rc=$?
+
+  if (( rc == 0 )); then
     return 0
   fi
 
+  if (( rc != 1 )); then
+    error "Failed to inspect section \"$header\" in \"$file\" !"
+    return 1
+  fi
+
   if [[ "$ending" == "crlf" ]]; then
     printf '%s\r\n' "$entry"
   else
@@ -2412,7 +2462,9 @@ addLegacyDrivers() {
   patchStorageDriver "$file" "$arch" || return 1
   addSataDriver "$dir" "$target" "$arch" "$drivers" "$file" || return 1
 
-  rm -rf "$drivers" || return 1
+  if ! rm -rf "$drivers"; then
+    warn "failed to clean temporary driver files!"
+  fi
 
   return 0
 }
@@ -2424,7 +2476,7 @@ setLegacyKey() {
   local arch="$3"
   local desc="$4"
 
-  local setup pid key file
+  local setup pid file block
   setup=$(find "$target" -maxdepth 1 -type f -iname setupp.ini -print -quit) || return 1
 
   [[ -n "$setup" ]] || return 0
@@ -2434,7 +2486,8 @@ setLegacyKey() {
   pid="${pid%$'\r'}"
 
   if [[ "$driver" == "2k" ]]; then
-    echo "${pid::-3}270" > "$setup" || return 1
+    [ "${#pid}" -ge 3 ] || return 0
+    echo "${pid::-3}270" > "$setup" || :
     return 0
   fi
 
@@ -2447,28 +2500,44 @@ setLegacyKey() {
 
   if [[ -n "$file" ]]; then
 
+    local key=""
+
     # Prefer a staging or OEM key already shipped on the media before falling
     # back to Microsoft's documented generic installation keys.
     if [[ "$driver" == "2k3" ]]; then
 
-      key=$(grep -i -A 2 "StagingKey" "$file" | tail -n 2 | head -n 1) || key=""
+      block=$(grep -i -A 2 "StagingKey" "$file") || block=""
+
+      if [ -n "$block" ]; then
+        key=$(printf '%s\n' "$block" | tail -n 2 | head -n 1) || key=""
+      fi
 
     else
 
       key="${pid: -8:5}"
 
       if [[ "${pid^^}" == *"OEM" ]]; then
-        key=$(grep -i -A 2 "$key" "$file" | tail -n 2 | head -n 1) || key=""
+
+        block=$(grep -i -A 2 "$key" "$file") || block=""
+
       else
-        key=$(grep -i -m 1 -A 2 "$key" "$file" | tail -n 2 | head -n 1) || key=""
+
+        block=$(grep -i -m 1 -A 2 "$key" "$file") || block=""
+
+      fi
+
+      if [ -n "$block" ]; then
+        key=$(printf '%s\n' "$block" | tail -n 2 | head -n 1) || key=""
       fi
 
       key="${key#*= }"
 
     fi
 
-    key="${key%$'\r'}"
-    [[ "${#key}" == "29" ]] && KEY="$key"
+    if [ -n "$key" ]; then
+      key="${key%$'\r'}"
+      [[ "${#key}" == "29" ]] && KEY="$key"
+    fi
 
   fi
 
@@ -2499,7 +2568,9 @@ setLegacyKey() {
 
   esac
 
-  echo "${pid::-3}000" > "$setup" || return 1
+  if [ "${#pid}" -ge 3 ]; then
+    echo "${pid::-3}000" > "$setup" || :
+  fi
 
   return 0
 }
@@ -2768,12 +2839,10 @@ disableAutoReboot() {
 
   local target="$1"
 
-  local file
+  local file rc=0
   local pattern='^[[:space:]]*HKLM[[:space:]]*,[[:space:]]*"SYSTEM\\CurrentControlSet\\Control\\CrashControl"[[:space:]]*,[[:space:]]*"AutoReboot"[[:space:]]*,[[:space:]]*[^,]*,'
 
-  file=$(find \
-    "$target" -maxdepth 1 -type f -iname HIVESYS.INF -print -quit
-  ) || return 1
+  file=$(find "$target" -maxdepth 1 -type f -iname HIVESYS.INF -print -quit) || return 1
 
   if [ -z "$file" ]; then
     error "The file HIVESYS.INF could not be found!"
@@ -2782,19 +2851,18 @@ disableAutoReboot() {
 
   # Keep setup crashes visible instead of immediately rebooting into an
   # opaque installation loop.
-  if grep -Eqi "${pattern}[[:space:]]*[^,;[:space:]]+" "$file"; then
+  grep -Eqi "${pattern}[[:space:]]*[^,;[:space:]]+" "$file" || rc=$?
 
-    sed -i -E \
-      "s|(${pattern})[[:space:]]*[^,;[:space:]]+|\\1 0|I" \
-      "$file" || return 1
-
-  else
-
-    printf '%s\n' \
-      'HKLM,"SYSTEM\CurrentControlSet\Control\CrashControl","AutoReboot",0x00010001,0' |
-      unix2dos >> "$file" || return 1
-
-  fi
+  case "$rc" in
+    0 )
+      sed -i -E "s|(${pattern})[[:space:]]*[^,;[:space:]]+|\\1 0|I" "$file" || :
+      ;;
+    1 )
+      printf '%s\n' \
+        'HKLM,"SYSTEM\CurrentControlSet\Control\CrashControl","AutoReboot",0x00010001,0' |
+        unix2dos >> "$file" || :
+      ;;
+  esac
 
   return 0
 }

src/define.sh

@@ -647,23 +647,28 @@ getVersion() {
   local evaluation=""
 
   id=$(fromName "$name" "$arch")
+  [ -z "$id" ] && return 0
+
   [[ "${name,,}" == *"evaluation"* ]] && evaluation="-eval"
 
   case "${id,,}" in
-    "winvista"* | "win7"* | "win8"* | "win10"* | "win11"* )
-      if edition=$(getEditionID "$name" "$id"); then
-        [ -n "$edition" ] && id+="-$edition"
-        [ -n "$evaluation" ] && id+="$evaluation"
-      fi
-      ;;
+
     "win20"* )
+
       if [[ "${name,,}" == *"hyper-v server"* ]]; then
         id+="-hv"
       elif edition=$(getServerEditionID "$name" "$id"); then
         [ -n "$edition" ] && id+="-$edition"
         [ -n "$evaluation" ] && id+="$evaluation"
-      fi
-      ;;
+      fi ;;
+
+    * )
+
+      if edition=$(getEditionID "$name" "$id"); then
+        [ -n "$edition" ] && id+="-$edition"
+        [ -n "$evaluation" ] && id+="$evaluation"
+      fi ;;
+
   esac
 
   echo "$id"
@@ -695,6 +700,7 @@ getEditionRank() {
 
   case "$base" in
     "win20"* )
+
       case "$edition" in
         "" ) echo 0 ;;
         "datacenter-azure-core" | "datacenter-azure-core-"* | \
@@ -709,9 +715,10 @@ getEditionRank() {
         "essentials" | "essentials-"* ) echo 5 ;;
         "hv" | "hv-"* ) echo 10 ;;
         * ) echo 99 ;;
-      esac
-      ;;
+      esac ;;
+
     * )
+
       case "$edition" in
         "enterprise-iot" | "enterprise-iot-"* | "iot" | "iot-"* ) echo 3 ;;
         "enterprise-ltsc" | "enterprise-ltsc-"* | "ltsc" | "ltsc-"* ) echo 4 ;;
@@ -723,8 +730,8 @@ getEditionRank() {
         "home" | "home-"* ) echo 6 ;;
         "starter" | "starter-"* ) echo 7 ;;
         * ) echo 99 ;;
-      esac
-      ;;
+      esac ;;
+
   esac
 
   return 0
@@ -735,6 +742,7 @@ getEditionPolicy() {
   local base="${1,,}"
 
   case "$base" in
+
     "win20"* )
       printf '%s\n' \
         "normalizeServerEditionID" \
@@ -750,9 +758,10 @@ getEditionPolicy() {
         "-datacenter-azure-core" \
         "-enterprise-core" \
         "-web-core" \
-        "-hv"
-      ;;
+        "-hv" ;;
+
     * )
+
       printf '%s\n' \
         "normalizeEditionID" \
         "-enterprise" \
@@ -764,8 +773,8 @@ getEditionPolicy() {
         "-home" \
         "-home-premium" \
         "-home-basic" \
-        "-starter"
-      ;;
+        "-starter" ;;
+
   esac
 
   return 0
@@ -774,18 +783,20 @@ getEditionPolicy() {
 normalizeEdition() {
 
   local source="${1,,}"
-
-  local edition
+  local edition transliterated
 
   source="${source//evaluation/}"
-  source=$(printf '%s' "$source" |
-    uconv -x 'Any-Latin; Latin-ASCII' 2>/dev/null) || return 1
+
+  if transliterated=$(printf '%s' "$source" |
+    uconv -x 'Any-Latin; Latin-ASCII' 2>/dev/null); then
+    source="$transliterated"
+  fi
 
   edition=$(sed -E \
     -e 's/[^a-z0-9]+/-/g' \
     -e 's/^-+//' \
     -e 's/-+$//' \
-    <<< "$source")
+    <<< "$source") || edition=""
 
   echo "$edition"
   return 0
@@ -799,11 +810,15 @@ normalizeEditionID() {
   edition=$(normalizeEdition "$1") || return 1
 
   case "$edition" in
+
     "pro" | "professional" | "business" )
       edition="" ;;
+
     "pro-n" | "pron" | "professional-n" | "professionaln" | "business-n" | "businessn" )
       edition="n" ;;
+
     * )
+
       if ! isClientEdition "$edition"; then
         case "$edition" in
           *"-n" ) base="${edition%-n}" ;;
@@ -816,10 +831,13 @@ normalizeEditionID() {
         fi
 
       fi ;;
+  
   esac
 
   case "${id,,}" in
+
     "win10"* | "win11"* )
+
       case "$edition" in
         "iot-enterprise-ltsc" | \
         "iot-enterprise-ltsc-"[0-9][0-9][0-9][0-9] )
@@ -827,8 +845,8 @@ normalizeEditionID() {
         "enterprise-ltsc" | \
         "enterprise-ltsc-"[0-9][0-9][0-9][0-9] )
           edition="ltsc" ;;
-      esac
-      ;;
+      esac ;;
+
   esac
 
   echo "$edition"

src/image.sh

@@ -273,13 +273,17 @@ detectLanguage() {
 
   for path in "${paths[@]}"; do
 
-    lang=$(xmlstarlet sel -T -t -v "normalize-space(string(($path)[1]))" - 2>/dev/null <<< "$xml") || lang=""
+    if ! lang=$(xmlstarlet sel -T -t -v "normalize-space(string(($path)[1]))" - 2>/dev/null <<< "$xml"); then
+      warn "failed to read language metadata from Windows image!"
+      return 0
+    fi
+
     [ -n "$lang" ] && break
 
   done
 
   if [ -z "$lang" ]; then
-    warn "Language could not be detected from ISO!"
+    warn "language could not be detected from ISO!"
     return 0
   fi
 
@@ -290,7 +294,7 @@ detectLanguage() {
     return 0
   fi
 
-  warn "Invalid language detected: \"$lang\""
+  warn "invalid language detected: \"$lang\""
   return 0
 }
 
@@ -617,7 +621,7 @@ detectLegacy() {
 
   if [ -n "$marker" ]; then
     error "Windows IA-64 (Itanium) images are not supported by this container!"
-    exit 67
+    return 2
   fi
 
   marker=$(find "$dir" -maxdepth 1 -type d -iname WIN95 -print -quit) || return 2
@@ -786,7 +790,6 @@ readWimHeader() {
 
   if ! rm -f -- "$header"; then
     enabled "$DEBUG" && echo "Failed to remove the previous temporary WIM header: $header" >&2
-    error "Failed to prepare Windows image header!"
     return 1
   fi
 
@@ -794,35 +797,30 @@ readWimHeader() {
   # extracting install.wim or install.esd from the ISO.
   if ! udfread range --ignore-case -o "$header" "$iso" "$image" 0 208 >/dev/null 2>&1; then
     enabled "$DEBUG" && echo "udfread failed to read the first 208 bytes of $image from $iso." >&2
-    error "Failed to read Windows image header!"
     rm -f -- "$header"
     return 1
   fi
 
   if ! size=$(stat -c%s -- "$header"); then
     enabled "$DEBUG" && echo "Failed to determine the size of the temporary WIM header: $header" >&2
-    error "Failed to read Windows image header!"
     rm -f -- "$header"
     return 1
   fi
 
   if (( size != 208 )); then
     enabled "$DEBUG" && echo "The WIM header is $size bytes instead of the expected 208 bytes." >&2
-    error "Failed to read Windows image header!"
     rm -f -- "$header"
     return 1
   fi
 
   if ! signature=$(od -An -N8 -tx1 "$header" | tr -d ' \n'); then
     enabled "$DEBUG" && echo "Failed to read the WIM header signature from $header." >&2
-    error "Failed to read Windows image header!"
     rm -f -- "$header"
     return 1
   fi
 
   if [[ "$signature" != "4d5357494d000000" ]]; then
     enabled "$DEBUG" && echo "The WIM header has an invalid signature: ${signature:-empty}." >&2
-    error "Failed to read Windows image header!"
     rm -f -- "$header"
     return 1
   fi
@@ -1241,7 +1239,7 @@ configureImage() {
 
   if [[ "$DETECTED" == "win81x86"* || "$DETECTED" == "win10x86"* ]]; then
     error "The 32-bit version of $desc is not supported!"
-    exit 67
+    return 2
   fi
 
   local msg="the answer file for $desc was not found ($DETECTED.xml)"
@@ -1269,18 +1267,14 @@ configureImage() {
 detectImageInfo() {
 
   local image_info="$1"
-
   local desc index rc
 
-  checkPlatform "$image_info" || {
-    enabled "$DEBUG" && echo "Platform validation failed for the Windows image metadata." >&2
-    exit 67
-  }
+  checkPlatform "$image_info" || return 2
 
   local output
   output=$(detectVersion "$image_info") || {
     enabled "$DEBUG" && echo "Version detection failed while parsing the Windows image metadata." >&2
-    error "Failed to detect Windows version from image metadata!"
+    error "Failed to detect the Windows version from image metadata!"
     return 1
   }
 
@@ -1292,16 +1286,18 @@ detectImageInfo() {
 
   validateEdition || {
     enabled "$DEBUG" && echo "Edition validation failed for detected image: ${DETECTED:-empty}, index: ${index:-empty}." >&2
-    error "Failed to validate Windows edition from image metadata!"
+    error "Failed to validate the Windows edition from image metadata!"
     return 1
   }
 
   if [ -z "$DETECTED" ]; then
+
     unknownImage || {
       rc=$?
       enabled "$DEBUG" && echo "Unknown-image handling failed after no Windows version could be detected (status $rc)." >&2
       return "$rc"
     }
+
     return 0
   fi
 
@@ -1337,25 +1333,84 @@ detectIsoImage() {
   # the caller may extract the media. Metadata parsing/configuration errors use 2.
   image=$(findIsoImage "$iso") || {
     rc=$?
-    enabled "$DEBUG" && echo "Direct ISO image lookup stopped with status $rc." >&2
+    enabled "$DEBUG" && echo "ISO image lookup failed (status $rc)." >&2
     return "$rc"
   }
 
   header=$(readWimHeader "$iso" "$image") || {
-    enabled "$DEBUG" && echo "Reading the WIM header failed for $image." >&2
+    error "Failed to read the Windows image header!"
     return 2
   }
 
   image_info=$(readIsoImageInfo "$iso" "$image" "$header") || {
-    enabled "$DEBUG" && echo "Reading the WIM XML metadata failed for $image." >&2
-    error "Failed to read Windows image metadata!"
+    error "Failed to read the Windows image metadata!"
     return 2
   }
 
   info "Detecting version from ISO image..."
 
   detectImageInfo "$image_info" || {
-    enabled "$DEBUG" && echo "Processing the Windows image metadata failed." >&2
+    error "Failed to process the Windows image metadata!"
+    return 2
+  }
+
+  return 0
+}
+
+detectESDImage() {
+
+  local iso="$1"
+
+  local image_info install_info output index rc
+  local -a detected=()
+
+  image_info=$(wimlib-imagex info "$iso" --xml 2>/dev/null |
+    iconv -f UTF-16LE -t UTF-8 2>/dev/null) || {
+    rc=$?
+    error "Cannot read ESD file information (status $rc)."
+    return 2
+  }
+
+  # Microsoft download ESDs use images 1-3 for setup media, WinPE, and Windows
+  # Setup; images 4 and higher contain installable editions.
+  if ! install_info=$(xmlstarlet ed \
+      -d '/WIM/IMAGE[number(@INDEX) < 4]' \
+      <<< "$image_info" 2>/dev/null); then
+    error "Cannot read installable images from ESD file!"
+    return 2
+  fi
+
+  checkPlatform "$install_info" || return 2
+
+  local output
+  output=$(detectVersion "$install_info") || {
+    error "Failed to detect Windows version from the ESD metadata!"
+    return 2
+  }
+
+  mapfile -t detected <<< "$output"
+  index="${detected[1]:-}"
+
+  if [ -z "$index" ]; then
+    error "Failed to select an installation image based on the ESD metadata!"
+    return 2
+  fi
+
+  # extractESD removes every other image, leaving the selected edition at
+  # index 1. Detect against that final layout so the generated answer file
+  # already references the index that will exist after extraction.
+  if ! image_info=$(xmlstarlet ed \
+      -d "/WIM/IMAGE[number(@INDEX) != $index]" \
+      -u "/WIM/IMAGE[@INDEX='$index']/@INDEX" -v '1' \
+      <<< "$install_info" 2>/dev/null); then
+    error "Cannot prepare ESD image information!"
+    return 2
+  fi
+
+  info "Detecting version from ESD image..."
+
+  detectImageInfo "$image_info" || {
+    error "Failed to process the ESD image metadata!"
     return 2
   }
 
@@ -1364,6 +1419,8 @@ detectIsoImage() {
 
 baseDir() {
 
+  # TODO: Can be removed with base image 7.45+
+
   local path="${1%/}"
 
   [[ -z "$path" || "$path" == "/" ]] && {
@@ -1584,7 +1641,7 @@ extractESD() {
       return 1
     fi
 
-    checkPlatform "$xml" || return
+    checkPlatform "$installXml" || return
 
     output=$(detectVersion "$installXml") || return
     mapfile -t detected <<< "$output"
@@ -1990,7 +2047,11 @@ buildImage() {
 
   base=$(basename "$BOOT")
   local out="$TMP/${base%.*}.tmp"
-  rm -f "$out"
+
+  if ! rm -f "$out"; then
+    error "Failed to remove temporary ISO image: $out"
+    return 1
+  fi
 
   desc=$(printVariant "$DETECTED" "ISO")
 

src/install.sh

@@ -3,20 +3,43 @@ set -Eeuo pipefail
 
 startWindows() {
 
-  parseVersion || exit 58
-  parseLanguage || exit 62
-  detectCustom || exit 64
+  parseVersion || {
+    error "Failed to parse the Windows version!"
+    exit 58
+  }
+
+  parseLanguage || {
+    error "Failed to parse the Windows language!"
+    exit 62
+  }
+
+  detectCustom || {
+    error "Failed to scan for custom installation media!"
+    exit 64
+  }
+
+  local rc=0
+  startInstall || rc=$?
+  (( rc > 1 )) && exit "$rc"
+
+  if (( rc )); then
+
+    bootWindows || {
+      error "Failed to boot Windows!"
+      exit 66
+    }
 
-  if ! startInstall; then
-    bootWindows || exit 66
     return 0
+
   fi
 
   if ! hasImage "$ISO"; then
+
     if ! downloadImage "$ISO" "$VERSION" "$LANGUAGE"; then
       removeImage "$ISO" || :
       exit 68
     fi
+
   fi
 
   local boot="$BOOT"
@@ -48,11 +71,12 @@ selectWindowsImage() {
   XML=""
   FB="falling back to manual installation!"
 
-  normalizeDetected || return 70
+  normalizeDetected || :
 
   if [ -n "$DETECTED" ]; then
 
     if ! setImage; then
+      error "Failed to configure the detected Windows image!"
       return 70
     fi
 
@@ -61,6 +85,7 @@ selectWindowsImage() {
     fi
 
     if ! extractImage "$iso" "$dir" "$VERSION"; then
+      error "Failed to extract the Windows installation image!"
       removeImage "$iso" || :
       return 72
     fi
@@ -76,11 +101,21 @@ selectWindowsImage() {
     detectIsoImage "$iso" && return 0
 
     rc=$?
-    (( rc == 1 )) || return 76
+    if (( rc != 1 )); then
+      error "Failed to inspect the Windows installation ISO!"
+      return 76
+    fi
+
+  elif [[ "${iso,,}" == *.esd ]]; then
+
+    detectESDImage "$iso" && return 0
+    error "Failed to inspect the Windows installation ESD!"
+    return 76
 
   fi
 
   if ! extractImage "$iso" "$dir" "$VERSION"; then
+    error "Failed to extract the Windows installation image!"
     removeImage "$iso" || :
     return 74
   fi
@@ -90,9 +125,15 @@ selectWindowsImage() {
   detectImage "$dir" && return 0
 
   rc=$?
-  (( rc == 1 )) || return 76
+  if (( rc != 1 )); then
+    error "Failed to detect the extracted Windows installation image!"
+    return 76
+  fi
 
-  skipUnattended "$dir" "$iso" "$boot" || return 76
+  skipUnattended "$dir" "$iso" "$boot" || {
+    error "Failed to fall back to manual installation!"
+    return 76
+  }
 
   handled=1
   return 0
@@ -108,24 +149,37 @@ configureMachine() {
   desc=$(printVariant "$DETECTED" "$DETECTED") || return 78
 
   if ! checkMemory "$DETECTED"; then
+
     if [ -z "$CUSTOM" ]; then
-      useOriginalImage "$iso" || return 79
+      useOriginalImage "$iso" || {
+        error "Failed to preserve the original installation image!"
+        return 79
+      }
     fi
+
     return 79
   fi
 
   if ! setMachine "$DETECTED" "$iso" "$dir" "$desc"; then
+    error "Failed to configure the virtual machine for $desc!"
     return 80
   fi
 
   if ! restoreMachineState; then
+    error "Failed to restore the saved machine state!"
     return 82
   fi
 
   if ! supportsUnattended "$DETECTED"; then
-    skipUnattended "$dir" "$iso" "$boot" "N" || return 83
+
+    skipUnattended "$dir" "$iso" "$boot" "N" || {
+      error "Failed to fall back to manual installation!"
+      return 83
+    }
+  
     handled=1
     return 0
+
   fi
 
   return 0
@@ -141,16 +195,23 @@ prepareWindowsImage() {
   if supportsXML "$DETECTED"; then
 
     if ! createOverlay "$XML" "$LANGUAGE" "$TMP/setup"; then
+      error "Failed to create the Windows setup overlay!"
       return 84
     fi
 
     if ! createSetupImage "$TMP/setup" "$STORAGE/setup.img"; then
+      error "Failed to create the Windows setup image!"
       return 86
     fi
 
     # Bootable ISOs can be reused unchanged with the generated setup image.
-    if (( ! extracted )); then
-      useOriginalImage "$iso" || return 88
+    if (( ! extracted )) && isDirectImage "$iso"; then
+
+      useOriginalImage "$iso" || {
+        error "Failed to preserve the original installation image!"
+        return 88
+      }
+
       return 0
     fi
 
@@ -158,28 +219,54 @@ prepareWindowsImage() {
 
   # Extracted modern sources and SIF-based legacy media require a clean rebuild.
   if (( ! extracted )); then
+
     if ! extractImage "$iso" "$dir" "$VERSION"; then
+      error "Failed to extract the Windows installation image!"
       removeImage "$iso" || :
       return 90
     fi
+  
   fi
 
   if ! prepareImage "$iso" "$dir"; then
+    error "Failed to prepare the Windows installation image!"
     return 92
   fi
 
-  removeImage "$iso" || return 96
-  buildImage "$dir" || return 98
+  removeImage "$iso" || {
+    error "Failed to remove the source installation image!"
+    return 96
+  }
+
+  buildImage "$dir" || {
+    error "Failed to build the Windows installation image!"
+    return 98
+  }
 
   return 0
 }
 
 bootWindows() {
 
-  restoreMachineState || return
-  restoreBootMode || return
-  restoreMachine || return
-  reserveSambaPorts || return
+  if ! restoreMachineState; then
+    error "Failed to restore the saved machine state!"
+    return 1
+  fi
+
+  if ! restoreBootMode; then
+    error "Failed to restore the saved boot mode!"
+    return 1
+  fi
+
+  if ! restoreMachine; then
+    error "Failed to restore the saved machine type!"
+    return 1
+  fi
+
+  if ! reserveSambaPorts; then
+    error "Failed to reserve Samba ports!"
+    return 1
+  fi
 
   return 0
 }
@@ -211,13 +298,17 @@ startInstall() {
       case "${boot,,}" in
         "windows."* )
           error "The download filename \"$file\" uses the reserved \"windows.*\" namespace!"
-          exit 58 ;;
+          return 58 ;;
       esac
 
     else
 
       local language
-      language=$(getLanguage "$LANGUAGE" "culture")
+      if ! language=$(getLanguage "$LANGUAGE" "culture"); then
+        error "Failed to determine the Windows language!"
+        return 62
+      fi
+
       language="${language%%-*}"
 
       if [ -n "$language" ] && [[ "${language,,}" != "en" ]]; then
@@ -235,28 +326,32 @@ startInstall() {
 
   if ! rm -rf -- "$TMP"; then
     error "Failed to remove directory \"$TMP\" !"
-    exit 50
+    return 50
   fi
 
   local setup="$STORAGE/setup.img"
 
   if ! rm -f -- "$setup" "${setup}.tmp"; then
     error "Failed to remove setup image \"$setup\" !"
-    exit 50
+    return 50
   fi
 
   local previousBase
   if ! previousBase=$(readState "base"); then
     error "Failed to read the previous installation state!"
-    exit 50
+    return 50
   fi
 
-  skipInstall "$BOOT" "$previousBase" && return 1
+  local rc=0
+  skipInstall "$BOOT" "$previousBase" || rc=$?
+
+  (( rc > 1 )) && return "$rc"
+  (( rc )) || return 1
 
   if [ -z "$previousBase" ] && hasData; then
 
     if enabled "$SHUTDOWN" && [ ! -f "$STORAGE/windows.boot" ]; then
-      discardPrevious "" || exit 50
+      discardPrevious "" || return 50
     else
       if ! backupPrevious ""; then
         warn "the backup was incomplete, continuing with installation..."
@@ -267,7 +362,7 @@ startInstall() {
 
   if ! makeDir "$TMP"; then
     error "Failed to create directory \"$TMP\" !"
-    exit 50
+    return 50
   fi
 
   if [ -z "$CUSTOM" ]; then
@@ -285,27 +380,27 @@ startInstall() {
   if [ -n "$CUSTOM" ] || [ ! -s "$BOOT" ]; then
     if ! rm -f -- "$BOOT"; then
       error "Failed to remove obsolete ISO file \"$BOOT\" !"
-      exit 50
+      return 50
     fi
   fi
 
   if ! find "$STORAGE" -maxdepth 1 -type f -iname 'data.*' -not -iname '*.iso' -delete; then
     error "Failed to remove obsolete disk files from \"$STORAGE\" !"
-    exit 50
+    return 50
   fi
 
   if ! find "$STORAGE" -maxdepth 1 -type f -iname 'windows.*' -not -iname '*.iso' -delete; then
     error "Failed to remove obsolete Windows files from \"$STORAGE\" !"
-    exit 50
+    return 50
   fi
 
   if ! find "$STORAGE" -maxdepth 1 -type f \( -iname '*.rom' -or -iname '*.vars' \) -delete; then
     error "Failed to remove obsolete firmware files from \"$STORAGE\" !"
-    exit 50
+    return 50
   fi
 
   if [ -z "$CUSTOM" ] && [[ "${VERSION,,}" != "http"* ]]; then
-    checkMemory "$VERSION" || exit 67
+    checkMemory "$VERSION" || return 67
   fi
 
   # Work from the temporary directory so the persistent source path can
@@ -313,7 +408,7 @@ startInstall() {
   if [ -z "$CUSTOM" ] && [ -f "$BOOT" ] && [ -s "$BOOT" ]; then
     if ! mv -f -- "$BOOT" "$ISO"; then
       error "Failed to move ISO file from \"$BOOT\" to \"$ISO\" !"
-      exit 50
+      return 50
     fi
   fi
 
@@ -333,7 +428,7 @@ skipUnattended() {
   # so they cannot use the manual-install fallback.
   if ! isDirectImage "$iso"; then
     error "Failed to boot \"$iso\" because it is not a directly bootable ISO image!"
-    exit 60
+    return 1
   fi
 
   # When automatic preparation fails, inspect extracted media to determine
@@ -382,7 +477,7 @@ skipInstall() {
 
       if ! writeState "base" "$previousBase"; then
         error "Failed to migrate the previous installation state!"
-        exit 50
+        return 50
       fi
 
     fi
@@ -390,10 +485,12 @@ skipInstall() {
     # Older releases may have left a rebuilt custom ISO at its synthetic source
     # identity. A completed installation no longer needs that installation media.
     if [[ "${previousBase,,}" == "windows."* ]] && hasData && [ -f "$marker" ]; then
+
       if ! rm -f -- "$STORAGE/$previousBase"; then
         error "Failed to remove obsolete ISO file \"$STORAGE/$previousBase\" !"
-        exit 50
+        return 50
       fi
+
     fi
 
     # A changed source invalidates an unfinished installation. Back up an
@@ -404,7 +501,7 @@ skipInstall() {
 
         if ! rm -f -- "$STORAGE/$previousBase"; then
           error "Failed to remove ISO file \"$STORAGE/$previousBase\" !"
-          exit 50
+          return 50
         fi
 
         return 1
@@ -430,7 +527,7 @@ skipInstall() {
       fi
 
       if enabled "$SHUTDOWN" && [ ! -f "$marker" ]; then
-        discardPrevious "$STORAGE/$previousBase" || exit 50
+        discardPrevious "$STORAGE/$previousBase" || return 50
         return 1
       fi
 
@@ -469,7 +566,10 @@ finishInstall() {
   fi
 
   local file="$STORAGE/windows.ver"
-  cp -f /etc/version "$file" || return 1
+  cp -f /etc/version "$file" || {
+    error "Failed to save the Windows installation version!"
+    return 1
+  }
 
   if ! setOwner "$file"; then
     warn "Failed to set the owner for \"$file\" !"
@@ -477,15 +577,23 @@ finishInstall() {
 
   if [[ "$boot" == "$STORAGE/"* ]]; then
     if [[ "$aborted" != [Yy1]* ]] || [ -z "$CUSTOM" ]; then
+
       base=$(basename "$boot")
-      writeState "base" "$base" || return 1
+      writeState "base" "$base" || {
+        error "Failed to save the Windows installation source!"
+        return 1
+      }
+
     fi
   fi
 
   if [[ "${PLATFORM,,}" == "x64" ]]; then
     if [[ "${BOOT_MODE,,}" == "windows_legacy" ]]; then
 
-      writeState "mode" "$BOOT_MODE" || return 1
+      writeState "mode" "$BOOT_MODE" || {
+        error "Failed to save the Windows boot mode!"
+        return 1
+      }
 
     else
 
@@ -496,14 +604,22 @@ finishInstall() {
       fi
 
       if (( secure )); then
+
         BOOT_MODE="windows_secure"
-        writeState "mode" "$BOOT_MODE" || return 1
+        writeState "mode" "$BOOT_MODE" || {
+          error "Failed to save the Windows boot mode!"
+          return 1
+        }
+
       fi
 
     fi
   fi
 
-  reserveSambaPorts || return 1
+  reserveSambaPorts || {
+    error "Failed to reserve Samba ports!"
+    return 1
+  }
 
   if ! rm -rf -- "$TMP"; then
     error "Failed to remove directory \"$TMP\" !"
@@ -516,7 +632,6 @@ finishInstall() {
 findFile() {
 
   local fname="$1"
-
   local dir file base
   local boot="$STORAGE/windows.boot"
 
@@ -896,7 +1011,12 @@ detectImage() {
   local image_info
   image_info=$(readImageInfo "$wim") || return $?
 
-  detectImageInfo "$image_info" || return 2
+  detectImageInfo "$image_info" || {
+    error "Failed to process the Windows image metadata!"
+    return 2
+  }
+
+  return 0
 }
 
 prepareImage() {
@@ -1212,7 +1332,10 @@ createOverlay() {
     return 1
   fi
 
-  addAnswerFile "$asset" "$language" "$stage" || return 1
+  addAnswerFile "$asset" "$language" "$stage" || {
+    error "Failed to include the Windows answer file!"
+    return 1
+  }
 
   return 0
 }
@@ -1309,8 +1432,8 @@ backupPrevious () {
     failed="Y"
   fi
 
-  [ -z "$(ls -A "$dir")" ] && rm -rf "$dir"
-  [ -z "$(ls -A "$root")" ] && rm -rf "$root"
+  rmdir "$dir" 2>/dev/null || :
+  rmdir "$root" 2>/dev/null || :
 
   [ -n "$failed" ] && return 1
 

src/mido.sh

@@ -175,13 +175,16 @@ downloadWindowsLink() {
     --max-filesize 100K \
     -- "$skuUrl") || return
 
-  # Let jq parsing failures propagate so malformed API data is not mistaken
-  # for a normal missing-result response. The same applies to the link data.
-  skuId=$(printf '%s\n' "$skuJson" | jq --arg LANG "$language" -r 'first(.Skus[]? | select(.Language == $LANG) | .Id) // empty') 2>/dev/null || return
+  skuId=$(printf '%s\n' "$skuJson" | jq --arg LANG "$language" -r 'first(.Skus[]? | select(.Language == $LANG) | .Id) // empty') 2>/dev/null || skuId=""
 
   if [ -z "$skuId" ] || [[ "${skuId,,}" == "null" ]]; then
-    language=$(getLanguage "$lang" "desc")
-    error "No download in the $language language available for $desc!"
+    if [[ "${lang,,}" != "en" && "${lang,,}" != "en-"* ]]; then
+      language=$(getLanguage "$lang" "desc")
+      error "No download in the $language language available for $desc!"
+    else
+      error "Microsoft server provided us no SKU ID in response to our request!"
+      info "Response: $skuJson"
+    fi
     return 1
   fi
 
@@ -214,10 +217,10 @@ downloadWindowsLink() {
     return 1
   fi
 
-  link=$(printf '%s\n' "$linkJson" | jq --argjson TYPE "$type" -r 'first(.ProductDownloadOptions[]? | select(.DownloadType == $TYPE) | .Uri) // empty') 2>/dev/null || return
+  link=$(printf '%s\n' "$linkJson" | jq --argjson TYPE "$type" -r 'first(.ProductDownloadOptions[]? | select(.DownloadType == $TYPE) | .Uri) // empty') 2>/dev/null || link=""
 
   if [ -z "$link" ] || [[ "${link,,}" == "null" ]]; then
-    error "Microsoft server gave us no download link to our request for an automated download!"
+    error "Microsoft server provided us no download link to our request for an automated download!"
     info "Response: $linkJson"
     return 1
   fi
@@ -287,7 +290,7 @@ downloadWindows() {
     grep -Eio "<option[^>]*value=[\"'][0-9]+[\"'][^>]*>[[:space:]]*Windows[^<]*" |
     sed -nE "s/.*value=[\"']([0-9]+)[\"'].*/\1/p" |
     sed -n '1p' |
-    cut -c 1-16) || return
+    cut -c 1-16) || productId=""
   enabled "$DEBUG" && echo "$productId"
 
   if [ -z "$productId" ]; then
@@ -1119,7 +1122,7 @@ verifyFile() {
     info "Successfully verified $type!" && return 0
   fi
 
-  error "The downloaded file has an unknown $algo checksum: $hash , as the expected value was: $check. Please report this at $SUPPORT/issues"
+  warn "the downloaded file has an unknown $algo checksum: $hash , as the expected value was: $check. Please report this at $SUPPORT/issues"
   return 1
 }
 
@@ -1280,7 +1283,11 @@ downloadImage() {
     desc=$(fromFile "$base")
     web_desc="$desc"
 
-    tryDownload "$iso" "$version" "" "" "$desc" "$seconds" "$web_desc" || return
+    tryDownload "$iso" "$version" "" "" "$desc" "$seconds" "$web_desc" || {
+      rc=$?
+      error "Failed to download the Windows image from the specified URL!"
+      return "$rc"
+    }
 
     return 0
   fi
@@ -1450,6 +1457,8 @@ downloadImage() {
 
   if [[ "$tried" == "n" ]]; then
     error "No download method is available for $desc!"
+  else
+    error "All download methods failed for $desc!"
   fi
 
   return 1