Improve handling of challenging file names when 'core.quotePath=true'

As described in issue #78 transcrypt could fail to properly handle:

- file names with non-ASCII characters when Git's configuration
  option 'core.quotePath' is set to 'true' (as it is by default)
- file names containing spaces

This change improves handling of non-ASCII or space characters in
filenames and adds a test to exercise and confirm the fix.

Changes in particular:

- fix handling of space characters in file name in pre-commit hook
- override repository's 'core.quotePath' setting in commands that
  output paths to ensure 'core.quotePath=false' is always applied
  even when 'core.quotePath' is explicitly or implicitly (default)
  set to true.

tests/_test_helper.bash

@@ -30,22 +30,22 @@ function nuke_git_repo {
 function cleanup_all {
   nuke_git_repo
   rm $BATS_TEST_DIRNAME/.gitattributes
-  rm $BATS_TEST_DIRNAME/sensitive_file
+  rm -f $BATS_TEST_DIRNAME/sensitive_file
 }
 
 function init_transcrypt {
   $BATS_TEST_DIRNAME/../transcrypt --cipher=aes-256-cbc --password=abc123 --yes
 }
 
 function encrypt_named_file {
-  filename=$1
+  filename="$1"
   content=$2
   if [ "$content" ]; then
-    echo "$content" > $filename
+    echo "$content" > "$filename"
   fi
-  echo "$filename filter=crypt diff=crypt merge=crypt" >> .gitattributes
-  git add .gitattributes $filename
-  git commit -m "Encrypt file $filename"
+  echo "\"$filename\" filter=crypt diff=crypt merge=crypt" >> .gitattributes
+  git add .gitattributes "$filename"
+  run git commit -m "Encrypt file \"$filename\""
 }
 
 function setup {

tests/test_crypt.bats

@@ -88,3 +88,46 @@ function check_repo_is_clean {
   [ "${lines[0]}" != "$SECRET_CONTENT" ]
   [ "${lines[0]}" = "$SECRET_CONTENT_ENC" ]
 }
+
+@test "crypt: handle challenging file names when 'core.quotePath=true'" {
+  # Set core.quotePath=true which is the Git default prior to encrypting a
+  # file with non-ASCII characters and spaces in the name, to confirm
+  # transcrypt can handle the file properly.
+  # For info about the 'core.quotePath' setting see
+  # https://git-scm.com/docs/git-config#Documentation/git-config.txt-corequotePath
+  git config --local --add core.quotePath true
+
+  FILENAME="Mig – røve"  # Danish
+  SECRET_CONTENT_ENC="U2FsdGVkX19Fp9SwTyQ+tz1OgHNIN0OJ+6sMgHIqPMzfdZ6rZ2iVquS293WnjJMx"
+
+  encrypt_named_file "$FILENAME" "$SECRET_CONTENT"
+  [[ "${lines[0]}" = *"Encrypt file \"$FILENAME\"" ]]
+
+  # Working copy is decrypted
+  run cat "$FILENAME"
+  [ "$status" -eq 0 ]
+  [ "${lines[0]}" = "$SECRET_CONTENT" ]
+
+  # Git internal copy is encrypted
+  run git show HEAD:"$FILENAME" --no-textconv
+  [ "$status" -eq 0 ]
+  [ "${lines[0]}" = "$SECRET_CONTENT_ENC" ]
+
+  # transcrypt --show-raw shows encrypted content
+  run ../transcrypt --show-raw "$FILENAME"
+  [ "$status" -eq 0 ]
+  [ "${lines[0]}" = "==> $FILENAME <==" ]
+  [ "${lines[1]}" = "$SECRET_CONTENT_ENC" ]
+
+  # git ls-crypt lists encrypted file
+  run git ls-crypt
+  [ "$status" -eq 0 ]
+  [ "${lines[0]}" = "$FILENAME" ]
+
+  # transcrypt --list lists encrypted file"
+  run ../transcrypt --list
+  [ "$status" -eq 0 ]
+  [ "${lines[0]}" = "$FILENAME" ]
+
+  rm "$FILENAME"
+}

tests/test_init.bats

@@ -53,7 +53,7 @@ SETUP_SKIP_INIT_TRANSCRYPT=1
   [ `git config --get diff.crypt.binary` = "true" ]
   [ `git config --get merge.renormalize` = "true" ]
 
-  [[ `git config --get alias.ls-crypt` = "!git ls-files"* ]]
+  [[ `git config --get alias.ls-crypt` = "!git -c core.quotePath=false ls-files"* ]]
 }
 
 @test "init: show details for --display" {

tests/test_pre_commit.bats

@@ -26,7 +26,7 @@ load $BATS_TEST_DIRNAME/_test_helper.bash
   run git log --format=oneline
   [ "$status" -eq 0 ]
   [[ "${lines[0]}" = *"Added more" ]]
-  [[ "${lines[1]}" = *"Encrypt file sensitive_file" ]]
+  [[ "${lines[1]}" = *"Encrypt file \"sensitive_file\"" ]]
 }
 
 @test "pre-commit: reject commit of encrypted file with unencrypted content" {

transcrypt

@@ -379,7 +379,8 @@ save_helper_hooks() {
 	cat <<-'EOF' >"$pre_commit_hook_installed"
 		#!/usr/bin/env bash
 		# Transcrypt pre-commit hook: fail if secret file in staging lacks the magic prefix "Salted" in B64
-		for secret_file in $(git ls-files | git check-attr --stdin filter | awk 'BEGIN { FS = ":" }; /crypt$/{ print $1 }'); do
+		IFS=$'\n'
+		for secret_file in $(git -c core.quotePath=false ls-files | git -c core.quotePath=false check-attr --stdin filter | awk 'BEGIN { FS = ":" }; /crypt$/{ print $1 }'); do
 		  # Get prefix of raw file in Git's index using the :FILENAME revision syntax
 		  firstbytes=$(git show :$secret_file | head -c 8)
 		  # An empty file does not need to be, and is not, encrypted
@@ -401,6 +402,7 @@ save_helper_hooks() {
 		    exit 1
 		  fi
 		done
+		unset IFS
 	EOF
 
 	# Activate hook by copying it to the pre-commit script name, if safe to do so
@@ -455,7 +457,7 @@ save_configuration() {
 	git config merge.crypt.name 'Merge transcrypt secret files'
 
 	# add a git alias for listing encrypted files
-	git config alias.ls-crypt "!git ls-files | git check-attr --stdin filter | awk 'BEGIN { FS = \":\" }; /crypt$/{ print \$1 }'"
+	git config alias.ls-crypt "!git -c core.quotePath=false ls-files | git -c core.quotePath=false check-attr --stdin filter | awk 'BEGIN { FS = \":\" }; /crypt$/{ print \$1 }'"
 }
 
 # display the current configuration settings
@@ -622,7 +624,7 @@ uninstall_transcrypt() {
 list_files() {
 	if [[ $IS_BARE == 'false' ]]; then
 		cd "$REPO" || die 1 'could not change into the "%s" directory' "$REPO"
-		git ls-files | git check-attr --stdin filter | awk 'BEGIN { FS = ":" }; /crypt$/{ print $1 }'
+		git -c core.quotePath=false ls-files | git -c core.quotePath=false check-attr --stdin filter | awk 'BEGIN { FS = ":" }; /crypt$/{ print $1 }'
 	fi
 }
 
@@ -631,8 +633,8 @@ show_raw_file() {
 	if [[ -f $show_file ]]; then
 		# ensure the file is currently being tracked
 		local escaped_file=${show_file//\//\\\/}
-		if git ls-files --others -- "$show_file" | awk "/${escaped_file}/{ exit 1 }"; then
-			file_paths=$(git ls-tree --name-only --full-name HEAD "$show_file")
+		if git -c core.quotePath=false ls-files --others -- "$show_file" | awk "/${escaped_file}/{ exit 1 }"; then
+			file_paths=$(git -c core.quotePath=false ls-tree --name-only --full-name HEAD "$show_file")
 		else
 			die 1 'the file "%s" is not currently being tracked by git' "$show_file"
 		fi