From 1db8b30b74b6dcb495fb75e67afb9124ff1e5bac Mon Sep 17 00:00:00 2001
From: Po Lu <luangruo@yahoo.com>
Date: Sat, 20 Apr 2024 20:44:30 +0800
Subject: [PATCH] Eliminate minor wart in EmacsService.java

* java/org/gnu/emacs/EmacsService.java (openContentUri): Replace
arg BYTES with URI and change its type to String.

* src/android.c (android_init_emacs_service):

* src/androidvfs.c (android_authority_name)
(android_authority_open): Adjust commentary and code to match.

(cherry picked from commit 571fd42d48a0d99b7b210bd218836bd2f6ce2ccf)
---
 java/org/gnu/emacs/EmacsService.java | 45 ++++++++--------------------
 src/android.c                        |  2 +-
 src/androidvfs.c                     | 32 +++++---------------
 3 files changed, 21 insertions(+), 58 deletions(-)

diff --git a/java/org/gnu/emacs/EmacsService.java b/java/org/gnu/emacs/EmacsService.java
index b1ec397bc41..2d4079c11b0 100644
--- a/java/org/gnu/emacs/EmacsService.java
+++ b/java/org/gnu/emacs/EmacsService.java
@@ -962,11 +962,13 @@ public final class EmacsService extends Service
      string; make it writable if WRITABLE, and readable if READABLE.
      Truncate the file if TRUNCATE.
 
-     Value is the resulting file descriptor or -1 upon failure.  */
+     Value is the resulting file descriptor or an exception will be
+     raised.  */
 
   public int
-  openContentUri (byte[] bytes, boolean writable, boolean readable,
+  openContentUri (String uri, boolean writable, boolean readable,
 		  boolean truncate)
+    throws FileNotFoundException, IOException
   {
     String name, mode;
     ParcelFileDescriptor fd;
@@ -985,39 +987,16 @@ public final class EmacsService extends Service
     if (truncate)
       mode += "t";
 
-    /* Try to open an associated ParcelFileDescriptor.  */
+    /* Try to open a corresponding ParcelFileDescriptor.  Though
+       `fd.detachFd' is exclusive to Honeycomb and up, this function is
+       never called on systems older than KitKat, which is Emacs's
+       minimum requirement for access to /content/by-authority.  */
 
-    try
-      {
-	/* The usual file name encoding question rears its ugly head
-	   again.  */
-
-	name = new String (bytes, "UTF-8");
-	fd = resolver.openFileDescriptor (Uri.parse (name), mode);
-
-	/* Use detachFd on newer versions of Android or plain old
-	   dup.  */
-
-	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1)
-	  {
-	    i = fd.detachFd ();
-	    fd.close ();
-
-	    return i;
-	  }
-	else
-	  {
-	    i = EmacsNative.dup (fd.getFd ());
-	    fd.close ();
+    fd = resolver.openFileDescriptor (Uri.parse (uri), mode);
+    i = fd.detachFd ();
+    fd.close ();
 
-	    return i;
-	  }
-      }
-    catch (Exception exception)
-      {
-	exception.printStackTrace ();
-	return -1;
-      }
+    return i;
   }
 
   /* Return whether Emacs is directly permitted to access the
diff --git a/src/android.c b/src/android.c
index 507ffc458d8..7a7eadc946a 100644
--- a/src/android.c
+++ b/src/android.c
@@ -1632,7 +1632,7 @@ android_init_emacs_service (void)
   FIND_METHOD (reset_ic, "resetIC",
 	       "(Lorg/gnu/emacs/EmacsWindow;I)V");
   FIND_METHOD (open_content_uri, "openContentUri",
-	       "([BZZZ)I");
+	       "(Ljava/lang/String;ZZZ)I");
   FIND_METHOD (check_content_uri, "checkContentUri",
 	       "(Ljava/lang/String;ZZ)Z");
   FIND_METHOD (query_battery, "queryBattery", "()[J");
diff --git a/src/androidvfs.c b/src/androidvfs.c
index 88ea345a298..9e65dd2b140 100644
--- a/src/androidvfs.c
+++ b/src/androidvfs.c
@@ -3130,8 +3130,10 @@ android_authority_name (struct android_vnode *vnode, char *name,
 	  return NULL;
 	}
 
-      /* NAME must be a valid JNI string, so that it can be encoded
-	 properly.  */
+      /* If the URI is not a valid JNI string, return immediately.  This
+	 should not be possible, since /content file names are encoded
+	 into JNI strings at the naming stage; the check is performed
+	 only out of an abundance of caution.  */
 
       if (android_verify_jni_string (name))
 	goto no_entry;
@@ -3169,7 +3171,6 @@ android_authority_open (struct android_vnode *vnode, int flags,
 			AAsset **asset)
 {
   struct android_authority_vnode *vp;
-  size_t length;
   jobject string;
   int fd;
   JNIEnv *env;
@@ -3189,22 +3190,11 @@ android_authority_open (struct android_vnode *vnode, int flags,
      feasible.  */
   env = android_java_env;
 
-  /* Allocate a buffer to hold the file name.  */
-  length = strlen (vp->uri);
-  string = (*env)->NewByteArray (env, length);
-  if (!string)
-    {
-      (*env)->ExceptionClear (env);
-      errno = ENOMEM;
-      return -1;
-    }
-
-  /* Copy the URI into this byte array.  */
-  (*env)->SetByteArrayRegion (env, string, 0, length,
-			      (jbyte *) vp->uri);
+  /* Allocate a JNI string to hold VP->uri.  */
+  string = (*env)->NewStringUTF (env, vp->uri);
+  android_exception_check ();
 
   /* Try to open the file descriptor.  */
-
   fd = (*env)->CallNonvirtualIntMethod (env, emacs_service,
 					service_class.class,
 					service_class.open_content_uri,
@@ -3215,13 +3205,7 @@ android_authority_open (struct android_vnode *vnode, int flags,
 					(jboolean) !(mode & O_WRONLY),
 					(jboolean) ((mode & O_TRUNC)
 						    != 0));
-  if ((*env)->ExceptionCheck (env))
-    {
-      (*env)->ExceptionClear (env);
-      errno = ENOMEM;
-      ANDROID_DELETE_LOCAL_REF (string);
-      return -1;
-    }
+  android_exception_check_1 (string);
 
   /* If fd is -1, just assume that the file does not exist,
      and return -1 with errno set to ENOENT.  */
-- 
2.39.5