Index: src/wal.c
==================================================================
--- src/wal.c
+++ src/wal.c
@@ -2069,10 +2069,16 @@
 
   /* The header was successfully read. Return zero. */
   return 0;
 }
 
+/*
+** This is the value that walTryBeginRead returns when it needs to
+** be retried.
+*/
+#define WAL_RETRY  (-1)
+
 /*
 ** Read the wal-index header from the wal-index and into pWal->hdr.
 ** If the wal-header appears to be corrupt, try to reconstruct the
 ** wal-index from the WAL before returning.
 **
@@ -2147,23 +2153,20 @@
     rc = SQLITE_CANTOPEN_BKPT;
   }
   if( pWal->bUnlocked ){
     if( rc!=SQLITE_OK ){
       walIndexClose(pWal, 0);
+      pWal->bUnlocked = 0;
+      assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );
+      if( rc==SQLITE_IOERR_SHORT_READ ) rc = WAL_RETRY;
     }
     pWal->exclusiveMode = WAL_NORMAL_MODE;
   }
 
   return rc;
 }
 
-/*
-** This is the value that walTryBeginRead returns when it needs to
-** be retried.
-*/
-#define WAL_RETRY  (-1)
-
 /*
 ** Open an "unlocked" transaction. An unlocked transaction is a read 
 ** transaction used by a read-only client in cases where the *-shm
 ** file cannot be mapped and its contents cannot be trusted. It is
 ** assumed that the *-wal file has been read and that a wal-index 

Index: test/walro2.test
==================================================================
--- test/walro2.test
+++ test/walro2.test
@@ -333,9 +333,62 @@
   do_test 5.3 {
     code1 { db close }
     code1 { tvfs delete }
   } {}
 
+  #-----------------------------------------------------------------------
+  #
+  #
+  catch { code1 { db close } }
+  catch { code2 { db2 close } }
+  catch { code3 { db3 close } }
+
+  do_test 6.1 {
+    code1 { forcedelete test.db }
+    code1 { sqlite3 db test.db }
+    sql1 {
+      PRAGMA journal_mode = wal;
+      CREATE TABLE t1(x);
+      INSERT INTO t1 VALUES('hello');
+      INSERT INTO t1 VALUES('world');
+      INSERT INTO t1 VALUES('!');
+      INSERT INTO t1 VALUES('world');
+      INSERT INTO t1 VALUES('hello');
+    }
+
+    forcecopy test.db test.db2
+    forcecopy test.db-wal test.db2-wal
+    forcecopy test.db-shm test.db2-shm
+    
+    code1 { db close }
+  } {}
+
+  do_test 6.2 {
+    code1 {
+      set ::nRem 5
+      proc handle_read {op args} {
+        if {$op=="xRead" && [file tail [lindex $args 0]]=="test.db2-wal"} {
+          incr ::nRem -1
+          if {$::nRem==0} {
+            code2 { sqlite3 db2 test.db2 }
+            sql2  { PRAGMA wal_checkpoint = truncate }
+          }
+        }
+        return "SQLITE_OK"
+      }
+      testvfs tvfs -fullshm 1
+
+      tvfs filter xRead
+      tvfs script handle_read
+
+      sqlite3 db file:test.db2?readonly_shm=1&vfs=tvfs
+      db eval { SELECT * FROM t1 }
+    }
+  } {hello world ! world hello}
 
+  do_test 6.3 {
+    code1 { db close }
+    code1 { tvfs delete }
+  } {}
 }
 
 finish_test