IMAP: Fix creating header values from a BODYSTRUCTURE item

mail/common/src/main/java/com/fsck/k9/mail/internet/MimeParameterEncoder.kt

@@ -138,14 +138,14 @@ object MimeParameterEncoder {
         return length
     }
 
-    private fun String.isToken() = when {
+    fun String.isToken() = when {
         isEmpty() -> false
         else -> all { it.isTokenChar() }
     }
 
     private fun String.isQuotable() = all { it.isQuotable() }
 
-    private fun String.quoted(): String {
+    fun String.quoted(): String {
         // quoted-string = [CFWS] DQUOTE *([FWS] qcontent) [FWS] DQUOTE [CFWS]
         // qcontent      = qtext / quoted-pair
         // quoted-pair   = ("\" (VCHAR / WSP))

mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/RealImapFolder.kt

@@ -15,6 +15,8 @@ import com.fsck.k9.mail.internet.MimeBodyPart
 import com.fsck.k9.mail.internet.MimeHeader
 import com.fsck.k9.mail.internet.MimeMessageHelper
 import com.fsck.k9.mail.internet.MimeMultipart
+import com.fsck.k9.mail.internet.MimeParameterEncoder.isToken
+import com.fsck.k9.mail.internet.MimeParameterEncoder.quoted
 import com.fsck.k9.mail.internet.MimeUtility
 import java.io.IOException
 import java.io.InputStream
@@ -889,7 +891,8 @@ internal class RealImapFolder(
                 for (i in bodyParams.indices step 2) {
                     val paramName = bodyParams.getString(i)
                     val paramValue = bodyParams.getString(i + 1)
-                    contentType.append(String.format(";\r\n %s=\"%s\"", paramName, paramValue))
+                    val encodedValue = if (paramValue.isToken()) paramValue else paramValue.quoted()
+                    contentType.append(String.format(";\r\n %s=%s", paramName, encodedValue))
                 }
             }
 
@@ -915,7 +918,8 @@ internal class RealImapFolder(
                     for (i in bodyDispositionParams.indices step 2) {
                         val paramName = bodyDispositionParams.getString(i).lowercase()
                         val paramValue = bodyDispositionParams.getString(i + 1)
-                        contentDisposition.append(String.format(";\r\n %s=\"%s\"", paramName, paramValue))
+                        val encodedValue = if (paramValue.isToken()) paramValue else paramValue.quoted()
+                        contentDisposition.append(String.format(";\r\n %s=%s", paramName, encodedValue))
                     }
                 }
             }

mail/protocols/imap/src/test/java/com/fsck/k9/mail/store/imap/RealImapFolderTest.kt

@@ -731,7 +731,83 @@ class RealImapFolderTest {
 
         folder.fetch(messages, fetchProfile, null, MAX_DOWNLOAD_SIZE)
 
-        verify(messages[0]).setHeader(MimeHeader.HEADER_CONTENT_TYPE, "text/plain;\r\n CHARSET=\"US-ASCII\"")
+        verify(messages[0]).setHeader(MimeHeader.HEADER_CONTENT_TYPE, "text/plain;\r\n CHARSET=US-ASCII")
+    }
+
+    @Test
+    fun `fetch() with simple content type parameter`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("text" "plain" ("name" "token") NIL NIL "7bit" 42 23)""",
+            headerName = MimeHeader.HEADER_CONTENT_TYPE,
+            expectedHeaderValue = "text/plain;\r\n name=token"
+        )
+    }
+
+    @Test
+    fun `fetch() with content type parameter that needs to be a quoted string`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("text" "plain" ("name" "one two three") NIL NIL "7bit" 42 23)""",
+            headerName = MimeHeader.HEADER_CONTENT_TYPE,
+            expectedHeaderValue = "text/plain;\r\n name=\"one two three\""
+        )
+    }
+
+    @Test
+    fun `fetch() with content type parameter that needs to be a quoted string with escaped characters`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("text" "plain" ("name" "one \"two\" three") NIL NIL "7bit" 42 23)""",
+            headerName = MimeHeader.HEADER_CONTENT_TYPE,
+            expectedHeaderValue = "text/plain;\r\n name=\"one \\\"two\\\" three\""
+        )
+    }
+
+    @Test
+    fun `fetch() with RFC 2231 encoded content type parameter`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("text" "plain" ("name*" "utf-8''filen%C3%A4me.ext") NIL NIL "7bit" 42 23)""",
+            headerName = MimeHeader.HEADER_CONTENT_TYPE,
+            expectedHeaderValue = "text/plain;\r\n name*=utf-8''filen%C3%A4me.ext"
+        )
+    }
+
+    @Test
+    fun `fetch() with simple content disposition parameter`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("application" "octet-stream" NIL NIL NIL "8bit" 23 NIL """ +
+                """("attachment" ("filename" "token")) NIL NIL)""",
+            headerName = MimeHeader.HEADER_CONTENT_DISPOSITION,
+            expectedHeaderValue = "attachment;\r\n filename=token;\r\n size=23"
+        )
+    }
+
+    @Test
+    fun `fetch() with content disposition parameter that needs to be a quoted string`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("application" "octet-stream" NIL NIL NIL "8bit" 23 NIL """ +
+                """("attachment" ("filename" "one two three")) NIL NIL)""",
+            headerName = MimeHeader.HEADER_CONTENT_DISPOSITION,
+            expectedHeaderValue = "attachment;\r\n filename=\"one two three\";\r\n size=23"
+        )
+    }
+
+    @Test
+    fun `fetch() with content disposition parameter that needs to be a quoted string with escaped characters`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("application" "octet-stream" NIL NIL NIL "8bit" 23 NIL """ +
+                """("attachment" ("filename" "one \"two\" three")) NIL NIL)""",
+            headerName = MimeHeader.HEADER_CONTENT_DISPOSITION,
+            expectedHeaderValue = "attachment;\r\n filename=\"one \\\"two\\\" three\";\r\n size=23"
+        )
+    }
+
+    @Test
+    fun `fetch() with RFC 2231 encoded content disposition parameter`() {
+        testHeaderFromBodyStructure(
+            bodyStructure = """("application" "octet-stream" NIL NIL NIL "8bit" 23 NIL """ +
+                """("attachment" ("filename*" "utf-8''filen%C3%A4me.ext")) NIL NIL)""",
+            headerName = MimeHeader.HEADER_CONTENT_DISPOSITION,
+            expectedHeaderValue = "attachment;\r\n filename*=utf-8''filen%C3%A4me.ext;\r\n size=23"
+        )
     }
 
     @Test
@@ -1118,6 +1194,22 @@ class RealImapFolderTest {
             .thenReturn(imapResponses)
     }
 
+    private fun testHeaderFromBodyStructure(bodyStructure: String, headerName: String, expectedHeaderValue: String) {
+        val folder = createFolder("Folder")
+        prepareImapFolderForOpen(OpenMode.READ_ONLY)
+        folder.open(OpenMode.READ_ONLY)
+        whenever(imapConnection.readResponse(anyOrNull()))
+            .thenReturn(createImapResponse("* 1 FETCH (BODYSTRUCTURE $bodyStructure UID 1)"))
+            .thenReturn(createImapResponse("x OK"))
+        val imapMessage = ImapMessage("1")
+        val messages = listOf(imapMessage)
+        val fetchProfile = createFetchProfile(FetchProfile.Item.STRUCTURE)
+
+        folder.fetch(messages, fetchProfile, null, MAX_DOWNLOAD_SIZE)
+
+        assertThat(imapMessage.getHeader(headerName)).asList().containsExactly(expectedHeaderValue)
+    }
+
     companion object {
         private const val MAX_DOWNLOAD_SIZE = -1
     }