Optimize root directory candidate parsing

Stream candidate paths directly into Bash read instead of storing all results and spawning two awk processes per candidate. This reduces process churn and memory usage on large extracted firmware trees while preserving paths containing spaces.

helpers/helpers_emba_prepare.sh

@@ -698,15 +698,14 @@ detect_root_dir_helper() {
     done
   fi
 
-  mapfile -t lROOTx_PATH_ARR < <(find "${lSEARCH_PATH}" -xdev \( -path "*/sbin" -o -path "*/bin" -o -path "*/lib" -o -path "*/etc" -o -path "*/root" -o -path "*/dev" -o -path "*/opt" -o -path "*/proc" -o -path "*/lib64" -o -path "*/boot" -o -path "*/home" \) -exec dirname {} \; | sort | uniq -c | sort -r)
   # currently not working: mapfile -t lROOTx_PATH_ARR < <(grep ";${lSEARCH_PATH}.*ELF" "${P99_CSV_LOG}" | grep "/bin/\|/lib/\|/etc/\|/root/\|/dev/\|/opt/\|/proc/\|/lib64\|/boot/\|/home/" | cut -d ';' -f2 | grep "${lSEARCH_PATH}" | sort -u || true)
-  for lR_PATH in "${lROOTx_PATH_ARR[@]}"; do
-    lCNT="$(awk '{print $1}' <<<"${lR_PATH}")" # field 1
+  # Stream and parse candidates with a shell builtin. Storing the entire list
+  # and spawning two awk processes per candidate is costly on large trees.
+  while IFS=' ' read -r lCNT lR_PATH; do
     if [[ "${lCNT}" -lt 5 ]]; then
       # we only use paths with more then 4 matches as possible root path
       continue
     fi
-    lR_PATH=$(awk '{print $2}' <<<"${lR_PATH}") # field 2
     if [[ -d "${lR_PATH}" ]]; then
       ROOT_PATH+=("${lR_PATH}")
       if [[ -z "${lMECHANISM}" ]]; then
@@ -715,7 +714,7 @@ detect_root_dir_helper() {
         lMECHANISM="${lMECHANISM} / dir names"
       fi
     fi
-  done
+  done < <(find "${lSEARCH_PATH}" -xdev \( -path "*/sbin" -o -path "*/bin" -o -path "*/lib" -o -path "*/etc" -o -path "*/root" -o -path "*/dev" -o -path "*/opt" -o -path "*/proc" -o -path "*/lib64" -o -path "*/boot" -o -path "*/home" \) -exec dirname {} \; | sort | uniq -c | sort -r)
 
   if [[ ${#ROOT_PATH[@]} -eq 0 ]]; then
     export RTOS=1

tests/helpers/prepare_helpers.bats

@@ -24,6 +24,24 @@ teardown() {
   teardown_emba_test_env
 }
 
+@test "detect_root_dir_helper handles strict-mode IFS and paths containing spaces" {
+  local lROOT_PATH="${LOG_DIR}/firmware root"
+  export P99_CSV_LOG="${CSV_DIR}/p99_prepare_analyzer.csv"
+  IFS=$'\n\t'
+  ROOT_PATH=()
+  mkdir -p "${lROOT_PATH}"/{bin,etc,home,lib,sbin}
+  touch "${P99_CSV_LOG}"
+
+  print_output() { :; }
+  write_link() { :; }
+
+  detect_root_dir_helper "${LOG_DIR}"
+
+  [ "${RTOS}" -eq 0 ]
+  [ "${#ROOT_PATH[@]}" -eq 1 ]
+  [ "${ROOT_PATH[0]}" = "${lROOT_PATH}" ]
+}
+
 @test "convert_timeformat converts days to seconds" {
   result="$(convert_timeformat "2d")"
   [ "${result}" = "$((2 * 24 * 3600))" ]