[System.Native] check ro.build.version.sdk_full for minor Android releases

src/libraries/System.Runtime/tests/System.Runtime.Extensions.Tests/System/EnvironmentTests.cs

@@ -170,6 +170,7 @@ public void OSVersion_ValidVersion()
         [InlineData("nelknet 4.15.0-24201807041620-generic", 4, 15, 0, int.MaxValue)] // integer overflow
         [InlineData("", 0, 0, 0, 0)]
         [InlineData("1abc", 1, 0, 0, 0)]
+        [InlineData("36.1", 36, 1, 0, 0)] // Android 36.1 minor SDK version
         public void OSVersion_ParseVersion(string input, int major, int minor, int build, int revision)
         {
             var getOSMethod = typeof(Environment).GetMethod("GetOperatingSystem", BindingFlags.Static | BindingFlags.NonPublic);
@@ -190,6 +191,25 @@ public void OSVersion_ValidVersion_OSX()
             Assert.Equal(-1, version.Revision); // Revision is never set on OSX
         }
 
+        [Fact]
+        [PlatformSpecific(TestPlatforms.Android)]
+        public void OSVersion_ValidVersion_AndroidMinor()
+        {
+            Version version = Environment.OSVersion.Version;
+
+            // Compare with what Java reports (if available)
+            string? javaVersion = Environment.GetEnvironmentVariable("DOTNET_ANDROID_VERSION_FROM_JAVA");
+            if (javaVersion != null)
+            {
+                // For Android, MonoRunner.java sets "36.1", so compare major and minor only
+                Assert.Equal(javaVersion, $"{version.Major}.{version.Minor}");
+            }
+            else
+            {
+                Assert.Fail("$DOTNET_ANDROID_VERSION_FROM_JAVA environment variable not set");
+            }
+        }
+
         [Fact]
         public void SystemPageSize_Valid()
         {

src/native/libs/System.Native/pal_runtimeinformation.c

@@ -21,7 +21,11 @@ char* SystemNative_GetUnixRelease(void)
 #if defined(TARGET_ANDROID)
     // get the Android API level
     char sdk_ver_str[PROP_VALUE_MAX];
-    if (__system_property_get("ro.build.version.sdk", sdk_ver_str))
+    if (__system_property_get("ro.build.version.sdk_full", sdk_ver_str))
+    {
+        return strdup(sdk_ver_str);
+    }
+    else if (__system_property_get("ro.build.version.sdk", sdk_ver_str))
     {
         return strdup(sdk_ver_str);
     }

src/tasks/AndroidAppBuilder/Templates/MonoRunner.java

@@ -94,6 +94,7 @@ public static void initializeRuntime(String entryPointLibName, Context context)
         setEnv("ASSETS_DIR", filesDir);
         setEnv("TMPDIR", cacheDir);
         setEnv("TEST_RESULTS_DIR", testResultsDir);
+        setEnv("DOTNET_ANDROID_VERSION_FROM_JAVA", getAndroidVersion());
 
         Log.i("DOTNET", "MonoRunner initializeRuntime, entryPointLibName=" + entryPointLibName);
         int localDateTimeOffset = getLocalDateTimeOffset();
@@ -188,6 +189,20 @@ static int getLocalDateTimeOffset() {
         }
     }
 
+    static String getAndroidVersion() {
+        String majorSdk = String.valueOf(android.os.Build.VERSION.SDK_INT);
+
+        // Check if Build.getMinorSdkVersion() is available (Android 16+ / API 36+)
+        if (android.os.Build.VERSION.SDK_INT >= 36) {
+            int minorSdk = android.os.Build.getMinorSdkVersion(android.os.Build.VERSION.SDK_INT_FULL);
+            if (minorSdk > 0) {
+                return majorSdk + "." + minorSdk;
+            }
+        }
+
+        return majorSdk + ".0";
+    }
+
     static native int setEnv(String key, String value);
 
     static native int initRuntime(String libsDir, String entryPointLibName, int local_date_time_offset);