From: drh <drh@noemail.net>
Date: Tue, 14 Nov 2017 03:42:52 +0000 (+0000)
Subject: Improvement to a comment.  No changes to code.
X-Git-Tag: version-3.22.0~199^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8b17ac1919afa4f2c73869e30f6938db775ea779;p=thirdparty%2Fsqlite.git

Improvement to a comment.  No changes to code.

FossilOrigin-Name: 486949fc03706e0056439b52ce60931ea4ce0a65e391da7f6287fe13862de251
---

diff --git a/manifest b/manifest
index fc71ea63a6..50ac558bb2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Remove\ssome\sbranches\sin\swalTryBeginRead()\sthat\swere\s\nadded\sby\scheck-in\s[ce5d13c2de]\sbut\sbecame\sunreachable\swith\sthe\saddition\nof\slogic\sin\scheck-in\s[18b26843]\sthat\senabled\sread-only\sclients\sto\sparse\nthe\sWAL\sfile\sinto\sa\sheap-memory\sWAL-index,\sthus\sguaranteeing\sthat\sthe\s\nWAL-index\sheader\sis\salways\savailable.
-D 2017-11-13T05:51:37.627
+C Improvement\sto\sa\scomment.\s\sNo\schanges\sto\scode.
+D 2017-11-14T03:42:52.056
 F Makefile.in 5bae3f2f3d42f2ad52b141562d74872c97ac0fca6c54953c91bb150a0e6427a8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 3a5cb477ec3ce5274663b693164e349db63348667cd45bad78cc13d580b691e2
@@ -543,7 +543,7 @@ F src/vdbesort.c 731a09e5cb9e96b70c394c1b7cf3860fbe84acca7682e178615eb941a3a0ef2
 F src/vdbetrace.c 48e11ebe040c6b41d146abed2602e3d00d621d7ebe4eb29b0a0f1617fd3c2f6c
 F src/vtab.c 0e4885495172e1bdf54b12cce23b395ac74ef5729031f15e1bc1e3e6b360ed1a
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c 31ae1a82afccf02e2ff220add690d057dd7e25d9d7ec0b53fe57f2d62a4ba510
+F src/wal.c beeb71e4eab65dbf0d95f2717efc6ca3c0f5b3090ce67f3de63828f39a6ff053
 F src/wal.h 8de5d2d3de0956d6f6cb48c83a4012d5f227b8fe940f3a349a4b7e85ebcb492a
 F src/walker.c d591e8a9ccf60abb010966b354fcea4aa08eba4d83675c2b281a8764c76cc22f
 F src/where.c b7a075f5fb3d912a891dcc3257f538372bb4a1622dd8ca7d752ad95ce8949ba4
@@ -1669,7 +1669,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 13ec8a77a47aa471af587459f4094da0d06674c5960f0d34777bcb3d38bc413b
-R be755a48b3ce9c3ee36556946fccdf2c
+P 9c6b38b9a96c11bdf9db4ea025720a4f49dcb723fa2e2776edc8453bce85c7e3
+R 696f834341714d48762ee99cfc8345fc
 U drh
-Z a296aa345abf23e8a36cfa010f746e55
+Z 27bc2b0f1009e1afc7034f11c759006b
diff --git a/manifest.uuid b/manifest.uuid
index 0dbf02629b..b0b16a61f7 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9c6b38b9a96c11bdf9db4ea025720a4f49dcb723fa2e2776edc8453bce85c7e3
\ No newline at end of file
+486949fc03706e0056439b52ce60931ea4ce0a65e391da7f6287fe13862de251
\ No newline at end of file
diff --git a/src/wal.c b/src/wal.c
index 382be4e0c8..376151e1a8 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -2178,6 +2178,9 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
       walIndexClose(pWal, 0);
       pWal->bShmUnreliable = 0;
       assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );
+      /* walIndexRecover() might have returned SHORT_READ if a concurrent
+      ** writer truncated the WAL out from under it.  If that happens, it
+      ** indicates that a writer has fixed the SHM file for us, so retry */
       if( rc==SQLITE_IOERR_SHORT_READ ) rc = WAL_RETRY;
     }
     pWal->exclusiveMode = WAL_NORMAL_MODE;