Fix an assertion fault in pcache introduced by [4bc93658aa563f2f] and

detected by OSSFuzz.  Test case in TH3.

FossilOrigin-Name: 2262a49467fa56c386080dac3e99a66e16c1700e138dba74db66e7b93ae76bf5

manifest

@@ -1,5 +1,5 @@
-C Have\sthe\splanner\sensure\sthat\sif\sone\sscan\suses\sa\ssubset\sof\sthe\sWHERE\sclause\sof\sanother,\sthat\sscan\sis\sestimated\sto\scost\sless\sand\sreturn\sfewer\srows.
-D 2021-08-31T15:53:58.805
+C Fix\san\sassertion\sfault\sin\spcache\sintroduced\sby\s[4bc93658aa563f2f]\sand\ndetected\sby\sOSSFuzz.\s\sTest\scase\sin\sTH3.
+D 2021-09-03T18:11:12.688
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -534,7 +534,7 @@ F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c 95c255256b13827caf038c8f963d334784073f38ab6ef9d70371d9d04f3c43e0
 F src/pager.h 4bf9b3213a4b2bebbced5eaa8b219cf25d4a82f385d093cd64b7e93e5285f66f
 F src/parse.y 86aa016b281f61d7664dd8cb7808cab8114d14cfaf362a9b9fc9ead8f33546b7
-F src/pcache.c 385ff064bca69789d199a98e2169445dc16e4291fa807babd61d4890c3b34177
+F src/pcache.c 084e638432c610f95aea72b8509f0845d2791293f39d1b82f0c0a7e089c3bb6b
 F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
 F src/pcache1.c 54881292a9a5db202b2c0ac541c5e3ef9a5e8c4f1c1383adb2601d5499a60e65
 F src/pragma.c c482a8d529d91e48ebdd5aa3bbbc15edd7f1cd4f4858613be9146866741ad2b8
@@ -1922,7 +1922,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 46e28cbcf6044b36aa4ddcda09adb49a46c6c6a8d41d558467ede3091304aa8c
-R 7a7a4eb3153f412c9a6ad188811a1057
-U dan
-Z 5dffd43884b54fa608822427de1e26e7
+P c7b34930e27597e7f634ad76be55fc436dcb84ea48d5b41b5d7f3596285dd672
+R 4f7910f5f5ef11dddc7f6d21ffbd4cd3
+U drh
+Z 3eac870735d941254d467d34517d396e

manifest.uuid

@@ -1 +1 @@
-c7b34930e27597e7f634ad76be55fc436dcb84ea48d5b41b5d7f3596285dd672
+2262a49467fa56c386080dac3e99a66e16c1700e138dba74db66e7b93ae76bf5

src/pcache.c

@@ -243,11 +243,14 @@ static int numberOfCachePages(PCache *p){
     ** suggested cache size is set to N. */
     return p->szCache;
   }else{
+    i64 n;
     /* IMPLEMANTATION-OF: R-59858-46238 If the argument N is negative, then the
     ** number of cache pages is adjusted to be a number of pages that would
     ** use approximately abs(N*1024) bytes of memory based on the current
     ** page size. */
-    return (int)((-1024*(i64)p->szCache)/(p->szPage+p->szExtra));
+    n = ((-1024*(i64)p->szCache)/(p->szPage+p->szExtra));
+    if( n>1000000000 ) n = 1000000000;
+    return (int)n;
   }
 }