Added 'modifyCustomIcons' helper

kotpass/src/main/kotlin/io/github/anvell/kotpass/database/modifiers/CustomIcons.kt

@@ -0,0 +1,26 @@
+package io.github.anvell.kotpass.database.modifiers
+
+import io.github.anvell.kotpass.database.KeePassDatabase
+import io.github.anvell.kotpass.models.CustomIcon
+import java.util.*
+
+/**
+ * Replaces [Map] of [CustomIcon] while removing invalid references in entries.
+ */
+inline fun KeePassDatabase.modifyCustomIcons(
+    crossinline block: (Map<UUID, CustomIcon>) -> Map<UUID, CustomIcon>
+): KeePassDatabase {
+    val newCustomIcons = block(content.meta.customIcons)
+    val removedUuids = content.meta.customIcons.keys
+        .filter { it !in newCustomIcons.keys }
+
+    return modifyEntries {
+        if (customIconUuid in removedUuids) {
+            copy(customIconUuid = null)
+        } else {
+            this
+        }
+    }.modifyMeta {
+        copy(customIcons = newCustomIcons)
+    }
+}

kotpass/src/test/kotlin/io/github/anvell/kotpass/database/modifiers/CustomIconsSpec.kt

@@ -0,0 +1,44 @@
+package io.github.anvell.kotpass.database.modifiers
+
+import io.github.anvell.kotpass.cryptography.EncryptedValue
+import io.github.anvell.kotpass.database.*
+import io.github.anvell.kotpass.io.decodeBase64ToArray
+import io.github.anvell.kotpass.models.CustomIcon
+import io.github.anvell.kotpass.models.Entry
+import io.github.anvell.kotpass.resources.DatabaseRes
+import io.kotest.core.spec.style.DescribeSpec
+import io.kotest.matchers.shouldBe
+import java.io.ByteArrayInputStream
+import java.util.*
+
+class CustomIconsSpec : DescribeSpec({
+
+    describe("CustomIcons modifier") {
+        it("Properly cleans up invalid references to custom icons") {
+            val uuid = UUID.randomUUID()
+            val customIcons = mapOf(
+                uuid to CustomIcon(byteArrayOf(0x1), null, null)
+            )
+            val database = KeePassDatabase.decode(
+                ByteArrayInputStream(DatabaseRes.DbVer4Argon2.decodeBase64ToArray()),
+                Credentials.from(EncryptedValue.fromString("1"))
+            ).modifyCustomIcons {
+                customIcons
+            }.modifyEntries {
+                copy(customIconUuid = uuid)
+            }
+            database.traverse { element ->
+                if (element is Entry) {
+                    element.customIconUuid shouldBe uuid
+                }
+            }
+            val noCustomIcons = database.modifyCustomIcons { mapOf() }
+
+            noCustomIcons.traverse { element ->
+                if (element is Entry) {
+                    element.customIconUuid shouldBe null
+                }
+            }
+        }
+    }
+})