Android: Prevent editing of files opened from a memory buffer.

Memory buffers are used for implementing content:// URLs, which are
(in most cases) readonly. If we ever encounter a read/write content://
URL in the future, we could consider supporting saving to it.

(An example of a content:// URI is an email attachment, where IPC is used
to transfer the file from the email client, rather than relying on a local
file).

1 files changed, 8 insertions, 0 deletions

diff --git a/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java b/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java
index 0532b61d..750540b7 100644
--- a/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java
+++ b/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java
@@ -22,6 +22,7 @@ public class MuPDFCore
 	private byte fileBuffer[];
 	private String file_format;
 	private boolean isUnencryptedPDF;
+	private final boolean wasOpenedFromBuffer;
 
 	/* The native functions */
 	private native long openFile(String filename);
@@ -112,6 +113,7 @@ public class MuPDFCore
 		}
 		file_format = fileFormatInternal();
 		isUnencryptedPDF = isUnencryptedPDFInternal();
+		wasOpenedFromBuffer = false;
 	}
 
 	public MuPDFCore(Context context, byte buffer[], String magic) throws Exception {
@@ -123,6 +125,7 @@ public class MuPDFCore
 		}
 		file_format = fileFormatInternal();
 		isUnencryptedPDF = isUnencryptedPDFInternal();
+		wasOpenedFromBuffer = true;
 	}
 
 	public  int countPages()
@@ -143,6 +146,11 @@ public class MuPDFCore
 		return isUnencryptedPDF;
 	}
 
+	public boolean wasOpenedFromBuffer()
+	{
+		return wasOpenedFromBuffer;
+	}
+
 	private synchronized int countPagesSynchronized() {
 		return countPagesInternal();
 	}