Add WITH_GMS_ALT setting as an alternative to WITH_GMS

Dockerfile

@@ -93,6 +93,20 @@ ENV ZIP_SUBDIR true
 # Write the verbose logs to $LOGS_DIR/$codename instead of $LOGS_DIR/
 ENV LOGS_SUBDIR true
 
+# Include microG's components in the ROM
+ENV WITH_GMS false
+
+# Include microG's components in the ROM providing free space for add-ons in system
+#
+# On newer devices running Android 10+ and using dynamic partitions, the size of
+# the system partition is defined by the ROM being flashed. For these devices,
+# regular LineageOS builds reserve some free space in the system partition
+# for add-ons such as GApps (typically 600MB). However, using WITH_GMS to include
+# microG's components in the ROM has the side effect of disabling this space
+# reservation, making later installation of add-ons impossible. Use WITH_GMS_ALT
+# as an alternative to WITH_GMS that does not disable space reservation in system.
+ENV WITH_GMS_ALT false
+
 # Apply the MicroG's signature spoofing patch
 # Valid values are "no", "yes" (for the original MicroG's patch) and
 # "restricted" (to grant the permission only to the system privileged apps).

src/build.sh

@@ -207,6 +207,16 @@ for branch in ${BRANCH_NAME//,/ }; do
     los_ver_minor=$(sed -n -e 's/^\s*PRODUCT_VERSION_MINOR = //p' "$makefile_containing_version")
     los_ver="$los_ver_major.$los_ver_minor"
 
+    # If needed, include microG's components while providing free space for add-ons in system
+    if [ "$WITH_GMS_ALT" = true ]; then
+      if [ "$WITH_GMS" = true ]; then
+        echo ">> [$(date)] ERROR: WITH_GMS and WITH_GMS_ALT cannot be both true"
+        exit 1
+      else
+        echo '$(call inherit-product, vendor/partner_gms/products/gms.mk)' > "vendor/$vendor/config/partner_gms.mk"
+      fi
+    fi
+
     # If needed, apply the microG's signature spoofing patch
     if [ "$SIGNATURE_SPOOFING" = "yes" ] || [ "$SIGNATURE_SPOOFING" = "restricted" ]; then
       # Determine which patch should be applied to the current Android source tree