SVN pre-revprop-change hook，不允许编辑的日志消息少于10个字符

Question

这是一个pre-revprop-change挂钩，我需要添加什么才能使编辑的日志消息少于10个字符？

@ECHO OFF
:: Set all parameters. Even though most are not used, in case you want to add
:: changes that allow, for example, editing of the author or addition of log messages.

set repository=%1
set revision=%2
set userName=%3
set propertyName=%4
set action=%5

:: Only allow the log message to be changed, but not author, etc.
if /I not "%propertyName%" == "svn:log" goto ERROR_PROPNAME

:: Only allow modification of a log message, not addition or deletion.
if /I not "%action%" == "M" goto ERROR_ACTION

:: Make sure that the new svn:log message is not empty.
set bIsEmpty=true
for /f "tokens=*" %%g in ('find /V ""') do (
set bIsEmpty=false
)
if "%bIsEmpty%" == "true" goto ERROR_EMPTY

goto :eof

:ERROR_EMPTY
echo Empty svn:log messages are not allowed. >&2
goto ERROR_EXIT

:ERROR_PROPNAME
echo Only changes to svn:log messages are allowed. >&2
goto ERROR_EXIT

:ERROR_ACTION
echo Only modifications to svn:log revision properties are allowed. >&2
goto ERROR_EXIT

:ERROR_EXIT
exit /b 1

我尝试添加一个计数器，将计数设置为0，最初如下：

:: Make sure that the new svn:log message is not empty.
for /f "tokens=*" %%g in ('find /V ""') do (
set "count=count+1"
)

if %count% lss 10 goto ERROR_EMPTY

但不知怎的，这似乎不起作用。