fix ots

android/app/build.gradle.kts

@@ -26,7 +26,8 @@ val hasGlyphSdk = glyphAar.isFile
  * `~/.gradle/gradle.properties`; neither should have to care which the build reads.
  */
 fun setting(name: String): String? =
-    (project.findProperty(name) as String?) ?: System.getenv(name)
+    (project.findProperty(name) as String?)?.takeIf { it.isNotBlank() }
+        ?: System.getenv(name)?.takeIf { it.isNotBlank() }
 
 /**
  * Successive builds have to install over each other, so the code has to climb.
@@ -74,10 +75,18 @@ android {
         create("release") {
             val storePath = setting("KADENCE_KEYSTORE")
             if (storePath != null && file(storePath).isFile) {
+                val storePassword = setting("KADENCE_KEYSTORE_PASSWORD")
+                    ?: throw GradleException(
+                        "KADENCE_KEYSTORE is set but KADENCE_KEYSTORE_PASSWORD is " +
+                            "missing or blank.",
+                    )
+                val keyPassword = setting("KADENCE_KEY_PASSWORD") ?: storePassword
+                val alias = setting("KADENCE_KEY_ALIAS") ?: "kadence"
+
                 storeFile = file(storePath)
-                storePassword = setting("KADENCE_KEYSTORE_PASSWORD")
-                keyAlias = setting("KADENCE_KEY_ALIAS") ?: "kadence"
-                keyPassword = setting("KADENCE_KEY_PASSWORD")
+                this.storePassword = storePassword
+                keyAlias = alias
+                this.keyPassword = keyPassword
             } else if (setting("KADENCE_REQUIRE_SIGNING") == "1") {
                 // Without this the fallback below quietly produces a *debug-signed*
                 // "release" APK: installable, apparently fine, and impossible to ship