KLIB: Fix reading property lists in Properties.propertyList()

1. If property is absent, or contains empty string or a string consisting only of whitespace characters, Properties.propertyList() should always return empty List<String>.
2. If property starts or ends with whitespace characters, Properties.propertyList() should not include empty-string values for whitespace prefix or suffix.

compiler/util-io/src/org/jetbrains/kotlin/konan/properties/Properties.kt

@@ -39,14 +39,16 @@ fun Properties.propertyString(key: String, suffix: String? = null): String? = ge
 
 /**
  * TODO: this method working with suffixes should be replaced with
- * functionality borrowed from def file parser and unified for interop tool
- * and kotlin compiler.
+ *  functionality borrowed from def file parser and unified for interop tool
+ *  and kotlin compiler.
  */
 fun Properties.propertyList(key: String, suffix: String? = null, escapeInQuotes: Boolean = false): List<String> {
-    val value = this.getProperty(key.suffix(suffix)) ?: this.getProperty(key)
-    if (value?.isBlank() == true) return emptyList()
-    return if (escapeInQuotes) value?.let { parseSpaceSeparatedArgs(it) } ?: emptyList()
-    else value?.split(Regex("\\s+")) ?: emptyList()
+    val value: String? = (getProperty(key.suffix(suffix)) ?: getProperty(key))?.trim(Char::isWhitespace)
+    return when {
+        value.isNullOrEmpty() -> emptyList()
+        escapeInQuotes -> parseSpaceSeparatedArgs(value)
+        else -> value.split(Regex("\\s+"))
+    }
 }
 
 fun Properties.hasProperty(key: String, suffix: String? = null): Boolean

compiler/util-io/src/org/jetbrains/kotlin/util/Util.kt

@@ -52,8 +52,8 @@ fun parseSpaceSeparatedArgs(argsString: String): List<String> {
     val parsedArgs = mutableListOf<String>()
     var inQuotes = false
     var currentCharSequence = StringBuilder()
-    fun saveArg() {
-        if (!currentCharSequence.isEmpty()) {
+    fun saveArg(wasInQuotes: Boolean) {
+        if (wasInQuotes || currentCharSequence.isNotBlank()) {
             parsedArgs.add(currentCharSequence.toString())
             currentCharSequence = StringBuilder()
         }
@@ -63,11 +63,11 @@ fun parseSpaceSeparatedArgs(argsString: String): List<String> {
             inQuotes = !inQuotes
             // Save value which was in quotes.
             if (!inQuotes) {
-                saveArg()
+                saveArg(true)
             }
-        } else if (char == ' ' && !inQuotes) {
+        } else if (char.isWhitespace() && !inQuotes) {
             // Space is separator.
-            saveArg()
+            saveArg(false)
         } else {
             currentCharSequence.append(char)
         }
@@ -75,6 +75,6 @@ fun parseSpaceSeparatedArgs(argsString: String): List<String> {
     if (inQuotes) {
         error("No close-quote was found in $currentCharSequence.")
     }
-    saveArg()
+    saveArg(false)
     return parsedArgs
-}
+}

compiler/util-klib/src/org/jetbrains/kotlin/library/KotlinLibrary.kt

@@ -67,7 +67,3 @@ val KotlinLibrary.packageFqName: String?
 
 val KotlinLibrary.exportForwardDeclarations
     get() = manifestProperties.propertyList(KLIB_PROPERTY_EXPORT_FORWARD_DECLARATIONS, escapeInQuotes = true)
-        .asSequence()
-        .map { it.trim() }
-        .filter { it.isNotEmpty() }
-        .toList()