The fix at [2bf5413dc2c19d5f] was incomplete in that it failed to clear

the reusable register cache that might contain registers in the STAT4
buffer region.  This additional change corrects the problem.
[forum:/forumpost/83cb4a95a0|Forum post 83cb4a95a0].  Test case in TH3.

FossilOrigin-Name: 5d554e4d0f59a4309fed40e4fb26c7be42f1d4d55ccdcaaf7b4d445aa3122955

1 files changed, 15 insertions, 0 deletions

diff --git a/src/analyze.c b/src/analyze.c
index 2eaabd6be..9e0a0c5e6 100644
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -1297,6 +1297,21 @@ static void analyzeOneTable(
         /* Allocate space to compute results for the largest index */
         pParse->nMem = MAX(pParse->nMem, regCol+mxCol);
         doOnce = 0;
+#ifdef SQLITE_DEBUG
+        /* Verify that setting pParse->nTempReg to zero below really
+        ** is needed in some cases, in order to excise all temporary
+        ** registers from the middle of the STAT4 buffer.  
+        ** https://sqlite.org/forum/forumpost/83cb4a95a0 (2023-03-25)
+        */
+        if( pParse->nTempReg>0 ){
+          int kk;
+          for(kk=0; kk<pParse->nTempReg; kk++){
+            int regT = pParse->aTempReg[kk];
+            testcase( regT>=regCol && regT<regCol+mxCol );
+          }
+        }
+#endif
+        pParse->nTempReg = 0;
       }
 
       addrNext = sqlite3VdbeCurrentAddr(v);