Windows build using appveyor (#467)

Same build script as manual build. See tools/win_installer
Only building i686 for now.

.appveyor.yml

@@ -0,0 +1,25 @@
+branches:
+  only:
+    - master
+
+# Start builds on tags only
+# skip_non_tags: true
+
+environment:
+  matrix:
+    - MSYS2_ARCH: i686
+      MSYSTEM: MINGW32
+
+build_script:
+  - set
+  - set PATH=C:\msys64\%MSYSTEM%\bin;C:\msys64\usr\bin;%PATH%
+  - set CHERE_INVOKING=yes
+  - bash -lc "pacman --noconfirm --ask 20 -Suy"
+  - bash -lc "bash .appveyor/msys2.sh"
+
+artifacts:
+  - path: tools/win_installer/gpodder-*-contents.txt
+  - path: tools/win_installer/gpodder-*-installer.exe
+  - path: tools/win_installer/gpodder-*-portable.exe
+
+deploy: off

.appveyor/msys2.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+cd tools/win_installer
+# bash -xe to also see commands
+bash -e ./build.sh "${APPVEYOR_REPO_COMMIT}"

tools/win_installer/_base.sh

@@ -33,7 +33,9 @@ function set_build_root {
     MINGW_ROOT="${BUILD_ROOT}/${MINGW}"
 }
 
-if [ -d "/home/IEUser" ]; then
+if [ "$APPVEYOR" == "True" ]; then
+	set_build_root "$HOME/_gpodder_build_root"
+elif [ -d "/home/IEUser" ]; then
 	set_build_root "/home/IEUser/_gpodder_build_root"
 else
 	set_build_root "${DIR}/_build_root"

tools/win_installer/build.sh

@@ -15,8 +15,10 @@ function main {
     [[ -d "${BUILD_ROOT}" ]] && (echo "${BUILD_ROOT} already exists"; exit 1)
 
     # started from the wrong env -> switch
-    if [ $(echo "$MSYSTEM" | tr '[A-Z]' '[a-z]') != "$MINGW" ]; then
+    if [ -n "$MSYSTEM" ] && [ $(echo "$MSYSTEM" | tr '[A-Z]' '[a-z]') != "$MINGW" ]; then
+        echo ">>>>> MSYSTEM=${MSYSTEM} - SWITCHING TO ${MINGW} <<<<"
         "/${MINGW}.exe" "$0"
+        echo ">>>>> DONE WITH ${MINGW} ?? <<<<"
         exit $?
     fi