Don't set environment variables until build.

The pkg-config variables can affect how a package is discovered, and if
set by a package that depends on another, could lead to the recursive
call to chocpkg producing the wrong result. Instead, set only when
specificly needed (by build or check_installed), and always invoke
commands by recursively invoking the script, never by function call.

chocpkg/chocpkg

@@ -55,6 +55,23 @@ dependencies() {
     DEPENDENCIES="$*"
 }
 
+# set_pkgconfig_paths sets the values of the PKG_CONFIG_PATH and
+# PKG_CONFIG_LIBDIR environment variables. This is deliberately only done
+# when needed, as otherwise the value could affect child builds when
+# recursing to build dependent packages.
+set_pkgconfig_paths() {
+    PKG_CONFIG_PATH="$PACKAGE_INSTALL_DIR/lib/pkgconfig:${PKG_CONFIG_PATH:-}"
+    export PKG_CONFIG_PATH
+
+    # When cross-compiling, reconfigure pkg-config to not look for .pc
+    # files in the standard system directories; only in our own build
+    # directory. It may be that a library is installed on the system
+    # but that is useless if it is for the wrong architecture.
+    if $IS_CROSS_COMPILE && [ "$PACKAGE_TYPE" = "target" ]; then
+        export PKG_CONFIG_LIBDIR=
+    fi
+}
+
 # Given a package name, find the pkgdef file associated with it, source
 # the contents of the file and set various variables.
 configure_for_package() {
@@ -88,21 +105,14 @@ configure_for_package() {
             error_exit "Unknown package type $PACKAGE_TYPE"
             ;;
     esac
-
-    # We must set PKG_CONFIG_PATH now so we know where to look for packages.
-    PKG_CONFIG_PATH="$PACKAGE_INSTALL_DIR/lib/pkgconfig:${PKG_CONFIG_PATH:-}"
-    export PKG_CONFIG_PATH
-
-    # When cross-compiling, reconfigure pkg-config to not look for .pc
-    # files in the standard system directories; only in our own build
-    # directory. It may be that a library is installed on the system
-    # but that is useless if it is for the wrong architecture.
-    if $IS_CROSS_COMPILE && [ "$PACKAGE_TYPE" = "target" ]; then
-        export PKG_CONFIG_LIBDIR=
-    fi
 }
 
-fetch_package() {
+cmd_installed() {
+    set_pkgconfig_paths
+    check_installed
+}
+
+cmd_fetch() {
     do_fetch
 }
 
@@ -130,9 +140,10 @@ prebuild_setup() {
     true
 }
 
-build_package() {
+cmd_build() {
+    set_pkgconfig_paths
     install_dependencies
-    fetch_package "$PACKAGE_NAME"
+    chocpkg fetch "$PACKAGE_NAME"
 
     echo =======================================================
     echo "Building $PACKAGE_NAME..."
@@ -149,16 +160,16 @@ build_package() {
     do_build
 }
 
-reinstall_package() {
-    build_package "$PACKAGE_NAME"
+cmd_reinstall() {
+    chocpkg build "$PACKAGE_NAME"
     cd "$PACKAGE_BUILD_DIR"
     do_install
 }
 
-install_package() {
+cmd_install() {
     # Already installed? Don't install again.
-    if ! check_installed; then
-        reinstall_package
+    if ! chocpkg installed "$PACKAGE_NAME"; then
+        chocpkg reinstall "$PACKAGE_NAME"
     fi
 }
 
@@ -171,20 +182,20 @@ cmd=$1; package=$2
 configure_for_package "$package"
 
 case "$cmd" in
+    installed)
+        cmd_installed
+        ;;
     fetch)
-        fetch_package
+        cmd_fetch
         ;;
     build)
-        build_package
+        cmd_build
         ;;
     reinstall)
-        reinstall_package
+        cmd_reinstall
         ;;
     install)
-        install_package
-        ;;
-    installed)
-        check_installed
+        cmd_install
         ;;
 esac