Index: src/os_unix.c
==================================================================
--- src/os_unix.c
+++ src/os_unix.c
@@ -550,11 +550,14 @@
 #endif
   }while( fd<0 && errno==EINTR );
   if( fd>=0 ){
     if( m!=0 ){
       struct stat statbuf;
-      if( osFstat(fd, &statbuf)==0 && (statbuf.st_mode&0777)!=m ){
+      if( osFstat(fd, &statbuf)==0 
+       && statbuf.st_size==0
+       && (statbuf.st_mode&0777)!=m 
+      ){
         osFchmod(fd, m);
       }
     }
 #if defined(FD_CLOEXEC) && (!defined(O_CLOEXEC) || O_CLOEXEC==0)
     osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);

Index: src/pager.c
==================================================================
--- src/pager.c
+++ src/pager.c
@@ -4825,10 +4825,15 @@
     }
     if( rc!=SQLITE_OK ){
       goto failed;
     }
     if( bHotJournal ){
+      if( pPager->readOnly ){
+        rc = SQLITE_READONLY_ROLLBACK;
+        goto failed;
+      }
+
       /* Get an EXCLUSIVE lock on the database file. At this point it is
       ** important that a RESERVED lock is not obtained on the way to the
       ** EXCLUSIVE lock. If it were, another process might open the
       ** database file, detect the RESERVED lock, and conclude that the
       ** database is safe to read while this process is still rolling the 

Index: src/sqlite.h.in
==================================================================
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -476,10 +476,11 @@
 #define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
 #define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
 #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
 #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
+#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
 #define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
 #define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
 #define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
 #define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
 #define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))

Index: src/test1.c
==================================================================
--- src/test1.c
+++ src/test1.c
@@ -176,10 +176,11 @@
                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
     case SQLITE_IOERR_LOCK:          zName = "SQLITE_IOERR_LOCK";        break;
     case SQLITE_CORRUPT_VTAB:        zName = "SQLITE_CORRUPT_VTAB";      break;
     case SQLITE_READONLY_RECOVERY:   zName = "SQLITE_READONLY_RECOVERY"; break;
     case SQLITE_READONLY_CANTLOCK:   zName = "SQLITE_READONLY_CANTLOCK"; break;
+    case SQLITE_READONLY_ROLLBACK:   zName = "SQLITE_READONLY_ROLLBACK"; break;
     default:                         zName = "SQLITE_Unknown";           break;
   }
   return zName;
 }
 #define t1ErrorName sqlite3TestErrorName

Index: test/misc7.test
==================================================================
--- test/misc7.test
+++ test/misc7.test
@@ -486,10 +486,38 @@
   set zFile [file join [get_pwd] "[string repeat abcde 104].db"]
   set rc [catch {sqlite3 db2 $zFile} msg]
   list $rc $msg
 } {1 {unable to open database file}}
 
+# Try to do hot-journal rollback with a read-only connection. The 
+# error code should be SQLITE_READONLY_ROLLBACK.
+#
+do_test misc7-22.1 {
+  db close
+  forcedelete test.db copy.db-journal
+  sqlite3 db test.db
+  execsql {
+    CREATE TABLE t1(a, b);
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(3, 4);
+  }
+  db close
+  sqlite3 db test.db -readonly 1
+  catchsql {
+    INSERT INTO t1 VALUES(5, 6);
+  }
+} {1 {attempt to write a readonly database}}
+do_test misc7-22.2 { execsql { SELECT * FROM t1 } } {1 2 3 4}
+do_test misc7-22.3 { 
+  set fd [open test.db-journal w]
+  puts $fd [string repeat abc 1000]
+  close $fd
+  catchsql { SELECT * FROM t1 }
+} {1 {attempt to write a readonly database}}
+do_test misc7-22.4 { 
+  sqlite3_extended_errcode db
+} SQLITE_READONLY_ROLLBACK
 
 db close
 forcedelete test.db
 
 finish_test

Index: test/pager1.test
==================================================================
--- test/pager1.test
+++ test/pager1.test
@@ -750,11 +750,11 @@
 db close
 sqlite3 db test.db -readonly 1
 do_catchsql_test pager1.4.5.6 {
   SELECT * FROM t1;
   SELECT * FROM t2;
-} {1 {disk I/O error}}
+} {1 {attempt to write a readonly database}}
 db close
 
 # Snapshot the file-system just before multi-file commit. Save the name
 # of the master journal file in $::mj_filename.
 #