sdk-installer: initialize pacman's keyring before calling pacman

A recent change in pacman invalidated the approach taken by Git for
Windows' SDK where we simply bundle the keyring as per Git for Windows'
maintainer's SDK. Instead, we now have to initialize the keyring
explicitly.

Reported by Lars Schneider.

This fixes git-for-windows/git#670

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

sdk-installer/release.sh

@@ -73,6 +73,8 @@ dlls_for_exes () {
 fileList="etc/nsswitch.conf \
 	etc/pacman.conf \
 	etc/pacman.d \
+	usr/bin/pacman-key \
+	usr/bin/tput.exe \
 	usr/bin/pacman.exe \
 	usr/bin/curl.exe \
 	usr/bin/gpg.exe \

sdk-installer/setup-git-sdk.bat

@@ -92,6 +92,13 @@
 	@EXIT 1
 )
 
+@REM we need a /tmp directory, just for the time being
+@MKDIR "%cwd%"\tmp
+
+@REM next, initialize pacman's keyring
+@"%cwd%"\usr\bin\bash.exe -l -c '/usr/bin/bash /usr/bin/pacman-key --init'
+@IF ERRORLEVEL 1 PAUSE
+
 @REM next, force update info
 @"%cwd%"\usr\bin\pacman -S --needed --force --noconfirm info
 
@@ -106,7 +113,6 @@
 	@EXIT 1
 )
 
-
 @REM next, force update pacman
 @"%cwd%"\usr\bin\pacman -S --needed --force --noconfirm pacman