Require tokens to be non-empty.

Followup to CL 272190935.

Fixes #3626 (again :))

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=273763774

Author: cpovirk

android/guava-tests/test/com/google/common/net/MediaTypeTest.java

@@ -148,22 +148,38 @@ public void testCreate_wildcardTypeDeclaredSubtype() {
     }
   }
 
-  public void testCreate_nonAsciiParameter() {
+  public void testCreate_nonAsciiType() {
     try {
       MediaType.create("…", "a");
       fail();
     } catch (IllegalArgumentException expected) {
     }
   }
 
-  public void testCreate_nonAsciiParameterValue() {
+  public void testCreate_nonAsciiSubtype() {
     try {
       MediaType.create("a", "…");
       fail();
     } catch (IllegalArgumentException expected) {
     }
   }
 
+  public void testCreate_emptyType() {
+    try {
+      MediaType.create("", "a");
+      fail();
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
+  public void testCreate_emptySubtype() {
+    try {
+      MediaType.create("a", "");
+      fail();
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
   public void testCreateApplicationType() {
     MediaType newType = MediaType.createApplicationType("yams");
     assertEquals("application", newType.type());
@@ -302,6 +318,15 @@ public void testWithParameter_nonAsciiParameterValue() {
     }
   }
 
+  public void testWithParameter_emptyParameter() {
+    MediaType mediaType = MediaType.parse("text/plain");
+    try {
+      mediaType.withParameter("", "a");
+      fail();
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
   public void testWithParametersIterable() {
     assertEquals(
         MediaType.parse("text/plain"),

android/guava/src/com/google/common/net/MediaType.java

@@ -949,6 +949,7 @@ static MediaType createVideoType(String subtype) {
 
   private static String normalizeToken(String token) {
     checkArgument(TOKEN_MATCHER.matchesAllOf(token));
+    checkArgument(!token.isEmpty());
     return Ascii.toLowerCase(token);
   }
 

guava-gwt/test/com/google/common/net/MediaTypeTest_gwt.java

@@ -43,6 +43,16 @@ public void testCreateVideoType() throws Exception {
   testCase.testCreateVideoType();
 }
 
+public void testCreate_emptySubtype() throws Exception {
+  com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
+  testCase.testCreate_emptySubtype();
+}
+
+public void testCreate_emptyType() throws Exception {
+  com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
+  testCase.testCreate_emptyType();
+}
+
 public void testCreate_invalidSubtype() throws Exception {
   com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
   testCase.testCreate_invalidSubtype();
@@ -53,14 +63,14 @@ public void testCreate_invalidType() throws Exception {
   testCase.testCreate_invalidType();
 }
 
-public void testCreate_nonAsciiParameter() throws Exception {
+public void testCreate_nonAsciiSubtype() throws Exception {
   com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
-  testCase.testCreate_nonAsciiParameter();
+  testCase.testCreate_nonAsciiSubtype();
 }
 
-public void testCreate_nonAsciiParameterValue() throws Exception {
+public void testCreate_nonAsciiType() throws Exception {
   com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
-  testCase.testCreate_nonAsciiParameterValue();
+  testCase.testCreate_nonAsciiType();
 }
 
 public void testCreate_wildcardTypeDeclaredSubtype() throws Exception {
@@ -143,6 +153,11 @@ public void testWithParameter() throws Exception {
   testCase.testWithParameter();
 }
 
+public void testWithParameter_emptyParameter() throws Exception {
+  com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
+  testCase.testWithParameter_emptyParameter();
+}
+
 public void testWithParameter_invalidAttribute() throws Exception {
   com.google.common.net.MediaTypeTest testCase = new com.google.common.net.MediaTypeTest();
   testCase.testWithParameter_invalidAttribute();

guava-tests/test/com/google/common/net/MediaTypeTest.java

@@ -148,22 +148,38 @@ public void testCreate_wildcardTypeDeclaredSubtype() {
     }
   }
 
-  public void testCreate_nonAsciiParameter() {
+  public void testCreate_nonAsciiType() {
     try {
       MediaType.create("…", "a");
       fail();
     } catch (IllegalArgumentException expected) {
     }
   }
 
-  public void testCreate_nonAsciiParameterValue() {
+  public void testCreate_nonAsciiSubtype() {
     try {
       MediaType.create("a", "…");
       fail();
     } catch (IllegalArgumentException expected) {
     }
   }
 
+  public void testCreate_emptyType() {
+    try {
+      MediaType.create("", "a");
+      fail();
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
+  public void testCreate_emptySubtype() {
+    try {
+      MediaType.create("a", "");
+      fail();
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
   public void testCreateApplicationType() {
     MediaType newType = MediaType.createApplicationType("yams");
     assertEquals("application", newType.type());
@@ -302,6 +318,15 @@ public void testWithParameter_nonAsciiParameterValue() {
     }
   }
 
+  public void testWithParameter_emptyParameter() {
+    MediaType mediaType = MediaType.parse("text/plain");
+    try {
+      mediaType.withParameter("", "a");
+      fail();
+    } catch (IllegalArgumentException expected) {
+    }
+  }
+
   public void testWithParametersIterable() {
     assertEquals(
         MediaType.parse("text/plain"),

guava/src/com/google/common/net/MediaType.java

@@ -949,6 +949,7 @@ static MediaType createVideoType(String subtype) {
 
   private static String normalizeToken(String token) {
     checkArgument(TOKEN_MATCHER.matchesAllOf(token));
+    checkArgument(!token.isEmpty());
     return Ascii.toLowerCase(token);
   }