Improved comment on cursorOwnsBtShared(). No changes to code.

FossilOrigin-Name: 5e269c2d2667df65592a32d6bc2fa388fd7eb181

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\sC99-ism\sand\sa\scompiler\swarning\sfor\sMSVC.
-D 2016-06-04T20:58:35.587
+C Improved\scomment\son\scursorOwnsBtShared().\s\sNo\schanges\sto\scode.
+D 2016-06-04T21:05:54.667
 F Makefile.in 7321ef0b584224781ec7731408857fa8962c32cc
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 831503fc4e988f571590af1405645fff121b5f1e
@@ -326,7 +326,7 @@ F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
 F src/backup.c 6df65fdd569c901a418887a1a76f82ec35044556
 F src/bitvec.c 3ee4c8b2c94ed3a7377256e18199e6ff5cf33f63
 F src/btmutex.c bc87dd3b062cc26edfe79918de2200ccb8d41e73
-F src/btree.c 579a8160f57db168425ef940276319bed48a95d3
+F src/btree.c b8875cff2d98d662a7e25d73483bccc2374d8bdb
 F src/btree.h 2107a2630e02c8cba58bb12ce14e731e734ea29c
 F src/btreeInt.h c18b7d2a3494695133e4e60ee36061d37f45d9a5
 F src/build.c e827e57e4a29c00e8429c5fd4d9d4572cb1b32a4
@@ -1500,7 +1500,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
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-R 7b13c2762e2abdaed13574cfe801f7ea
+P aa53a36ea2eb90cc4939e37e6ad320b4211692fd
+R 31679baf828d6d3e0ee835dac82e6874
 U drh
-Z c33407f01f615b8db559b27222022193
+Z bd564a0c26801286c1f95fad1a35ec86

manifest.uuid

@@ -1 +1 @@
-aa53a36ea2eb90cc4939e37e6ad320b4211692fd
+5e269c2d2667df65592a32d6bc2fa388fd7eb181

src/btree.c

@@ -450,6 +450,15 @@ static void releasePage(MemPage *pPage);  /* Forward reference */
 static int cursorHoldsMutex(BtCursor *p){
   return sqlite3_mutex_held(p->pBt->mutex);
 }
+
+/* Verify that the cursor and the BtShared agree about what is the current
+** database connetion. This is important in shared-cache mode. If the database 
+** connection pointers get out-of-sync, it is possible for routines like
+** btreeInitPage() to reference an stale connection pointer that references a
+** a connection that has already closed.  This routine is used inside assert()
+** statements only and for the purpose of double-checking that the btree code
+** does keep the database connection pointers up-to-date.
+*/
 static int cursorOwnsBtShared(BtCursor *p){
   assert( cursorHoldsMutex(p) );
   return (p->pBtree->db==p->pBt->db);