Windows: a test_cmp that is agnostic to random LF <> CRLF conversions

In a number of tests, output that was produced by a shell script is
compared to expected output using test_cmp. Unfortunately, the MSYS bash--
when invoked via git, such as in hooks--converts LF to CRLF on output
(as produced by echo and printf), which leads to many false positives.

Implements a diff tool that undoes the converted CRLF. To avoid that
sub-processes are spawned (which is very slow on Windows), the tool is
implemented as a shell function. Diff is invoked as usual only when a
difference is detected by the shell code.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Johannes Sixt 2013-10-26 21:17:15 +02:00 коммит произвёл Junio C Hamano
Родитель ce1a0473e8
Коммит 4d715ac05c
2 изменённых файлов: 67 добавлений и 0 удалений

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@ -710,3 +710,69 @@ test_ln_s_add () {
git update-index --add --cacheinfo 120000 $ln_s_obj "$2"
fi
}
# The following mingw_* functions obey POSIX shell syntax, but are actually
# bash scripts, and are meant to be used only with bash on Windows.
# A test_cmp function that treats LF and CRLF equal and avoids to fork
# diff when possible.
mingw_test_cmp () {
# Read text into shell variables and compare them. If the results
# are different, use regular diff to report the difference.
local test_cmp_a= test_cmp_b=
# When text came from stdin (one argument is '-') we must feed it
# to diff.
local stdin_for_diff=
# Since it is difficult to detect the difference between an
# empty input file and a failure to read the files, we go straight
# to diff if one of the inputs is empty.
if test -s "$1" && test -s "$2"
then
# regular case: both files non-empty
mingw_read_file_strip_cr_ test_cmp_a <"$1"
mingw_read_file_strip_cr_ test_cmp_b <"$2"
elif test -s "$1" && test "$2" = -
then
# read 2nd file from stdin
mingw_read_file_strip_cr_ test_cmp_a <"$1"
mingw_read_file_strip_cr_ test_cmp_b
stdin_for_diff='<<<"$test_cmp_b"'
elif test "$1" = - && test -s "$2"
then
# read 1st file from stdin
mingw_read_file_strip_cr_ test_cmp_a
mingw_read_file_strip_cr_ test_cmp_b <"$2"
stdin_for_diff='<<<"$test_cmp_a"'
fi
test -n "$test_cmp_a" &&
test -n "$test_cmp_b" &&
test "$test_cmp_a" = "$test_cmp_b" ||
eval "diff -u \"\$@\" $stdin_for_diff"
}
# $1 is the name of the shell variable to fill in
mingw_read_file_strip_cr_ () {
# Read line-wise using LF as the line separator
# and use IFS to strip CR.
local line
while :
do
if IFS=$'\r' read -r -d $'\n' line
then
# good
line=$line$'\n'
else
# we get here at EOF, but also if the last line
# was not terminated by LF; in the latter case,
# some text was read
if test -z "$line"
then
# EOF, really
break
fi
fi
eval "$1=\$$1\$line"
done
}

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@ -817,6 +817,7 @@ case $(uname -s) in
test_set_prereq NOT_CYGWIN
test_set_prereq SED_STRIPS_CR
test_set_prereq GREP_STRIPS_CR
GIT_TEST_CMP=mingw_test_cmp
;;
*CYGWIN*)
test_set_prereq POSIXPERM