From: drh <drh@noemail.net>
Date: Fri, 30 Dec 2016 13:55:50 +0000 (+0000)
Subject: Clarify the expectations for the behavior of the xFetch method on the
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2Fpcache1-zero-page;p=thirdparty%2Fsqlite.git

Clarify the expectations for the behavior of the xFetch method on the
sqlite3_pcache_methods object for the case when the key is zero.

FossilOrigin-Name: b0810ac1b22226a0ffcf73868779d7e98b5d8263
---

diff --git a/manifest b/manifest
index c9737ac295..81a46bacb4 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improved\sdetection\sof\szero\spage\snumbers\sin\sthe\spage\scache.
-D 2016-12-30T13:40:41.684
+C Clarify\sthe\sexpectations\sfor\sthe\sbehavior\sof\sthe\sxFetch\smethod\son\sthe\nsqlite3_pcache_methods\sobject\sfor\sthe\scase\swhen\sthe\skey\sis\szero.
+D 2016-12-30T13:55:50.562
 F Makefile.in 41bd4cad981487345c4a84081074bcdb876e4b2e
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -390,7 +390,7 @@ F src/resolve.c bb070cf5f23611c44ab7e4788803684e385fc3fb
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
 F src/select.c dfb6cadc3dcfba1b1bdbfba62ebba2b4b673413e
 F src/shell.c 6095531aa900decdaa765e0f3993fba7153c92c1
-F src/sqlite.h.in e8e2d108d82647f0a812fdb74accf91c1ec08ddc
+F src/sqlite.h.in c50b91a917b5a78469e0910a539cf84087ba821e
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 8648034aa702469afb553231677306cc6492a1ae
 F src/sqliteInt.h 2075e22d50833ca2d9956d0b7a6bfb845ad05dd2
@@ -1540,7 +1540,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 2842bc60538369f888c7df8365858c910322277d
-R 055be9062a2560beea507ce779b9565f
+P 5550e815dd943b15c3b08f0526280bba76976199
+R 40395c430e6a26d64841635be7560ef8
 U drh
-Z 9a04ffa20091cdf405452df841cb044b
+Z b0285f49e100b02afd5ae0bacab221f8
diff --git a/manifest.uuid b/manifest.uuid
index 6b1586a252..ca8a6f6376 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-5550e815dd943b15c3b08f0526280bba76976199
\ No newline at end of file
+b0810ac1b22226a0ffcf73868779d7e98b5d8263
\ No newline at end of file
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index caa89721e1..ed812294f7 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -7215,7 +7215,8 @@ struct sqlite3_pcache_page {
 ** for each entry in the page cache.
 **
 ** The page to be fetched is determined by the key. ^The minimum key value
-** is 1.  After it has been retrieved using xFetch, the page is considered
+** is 1.  The xFetch() method must return NULL if passed a key of 0.
+** After it has been retrieved using xFetch, the page is considered
 ** to be "pinned".
 **
 ** If the requested page is already in the page cache, then the page cache
@@ -7227,10 +7228,11 @@ struct sqlite3_pcache_page {
 ** <table border=1 width=85% align=center>
 ** <tr><th> createFlag <th> Behavior when page is not already in cache
 ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
-** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
-**                 Otherwise return NULL.
+** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so
+**                 and the key is not zero.  Otherwise return NULL.
 ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
-**                 NULL if allocating a new page is effectively impossible.
+**                 NULL if the key is zero or if allocating a new page is 
+**                 effectively impossible.
 ** </table>
 **
 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite