Rewrite the (debugging use only) sqlite3VdbeMemPrettyPrint() function to use

the safer StrAccum interface rather than writing directly into a static string
buffer.  Perhaps this will address ticket [bbd55a97e66ff50d], which we are
unable to reproduce.

FossilOrigin-Name: 69f6a7e42f42116d29514239575ee1dc381b5b673da012cb5f3e8cf17922d493

manifest

@@ -1,5 +1,5 @@
-C Backout\schange\s[4d0b9109f7a5312d4e1]\sbecause\sthe\sconditional\sit\sadded\sis\nno\slonger\sreachable\sdue\sto\scheck-in\s[1409758f72c0206c].
+C Rewrite\sthe\s(debugging\suse\sonly)\ssqlite3VdbeMemPrettyPrint()\sfunction\sto\suse\nthe\ssafer\sStrAccum\sinterface\srather\sthan\swriting\sdirectly\sinto\sa\sstatic\sstring\nbuffer.\s\sPerhaps\sthis\swill\saddress\sticket\s[bbd55a97e66ff50d],\swhich\swe\sare\nunable\sto\sreproduce.
-D 2020-01-06T18:59:46.667
+D 2020-01-06T19:23:41.424
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -597,12 +597,12 @@ F src/treeview.c 2f712c821748dccced8977c33de83146e75a193afd17da3da8ad64e0225fee2
 F src/trigger.c a40d50e88bd3355f1d2a73f0a3b2d6b42eae26ca4219001b82ef0d064439badc
 F src/update.c 9ad19af96aff95dc02a923a99f97c1bc0b909009a29a2914b796f786b9ac0c60
 F src/upsert.c 2920de71b20f04fe25eb00b655d086f0ba60ea133c59d7fa3325c49838818e78
-F src/utf.c 2f0fac345c7660d5c5bd3df9e9d8d33d4c27f366bcfb09e07443064d751a0507
+F src/utf.c 736ff76753236ffbc8b5b939f5e0607f28aeaa7c780b3a56b419228f0a81c87b
 F src/util.c 2c92bc706bbdb1c45a25180291e7e05a56e297aa5dd7b2bcd2b1c47e8bb05b17
 F src/vacuum.c 82dcec9e7b1afa980288718ad11bc499651c722d7b9f32933c4d694d91cb6ebf
-F src/vdbe.c d0e32097985670ff4afee241f2c1f6f466fe12b41f9c2d6a014ec0ba8a793f6f
+F src/vdbe.c 805988536c0c85c210455f1e9b568bf3418f64406229a3e8d24a0765bcb46e0a
 F src/vdbe.h defd693289c7bb8d325f109be9490c77138061211a116827da7244b6015a4934
-F src/vdbeInt.h e02ccac0334f7c71c952210657e6e18de1917605887c7bc6167a80a17f62da18
+F src/vdbeInt.h 30d3e8b991547cdf39025e416a0a737b0416d46747af70ae058f60e2e0466fe7
 F src/vdbeapi.c 1252d80c548711e47a6d84dae88ed4e95d3fbb4e7bd0eaa1347299af7efddf02
 F src/vdbeaux.c 3b2076c59217f964ff5fca348fa3f69c3157cbd5cafc549e9ea3252d8613c6a9
 F src/vdbeblob.c 253ed82894924c362a7fa3079551d3554cd1cdace39aa833da77d3bc67e7c1b1
@@ -1853,8 +1853,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 55c136ef61f23a04be1bf351ab7f6bdfa033653c32557a04916cc9770453f261
+P b3f2696705cc3e7b038f156423f808432a4680ea7e313dc15e34bdf6b1845655
-Q -4d0b9109f7a5312d4e136395e08b11dad64d746bc106ad44d47675e5b1dcb4ef
+R 90b6bd1ba31a9b128a324665d5b94d50
-R b0c8464788812694c740c6af7f1efb3b
 U drh
-Z c8dd5390dd99c1b482b234ca2073b61f
+Z 0e567cdf08d226c28800a15ad21e7761

manifest.uuid

@@ -1 +1 @@
-b3f2696705cc3e7b038f156423f808432a4680ea7e313dc15e34bdf6b1845655
+69f6a7e42f42116d29514239575ee1dc381b5b673da012cb5f3e8cf17922d493

src/utf.c

@@ -215,9 +215,11 @@ SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
 
 #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
   {
-    char zBuf[100];
+    StrAccum acc;
-    sqlite3VdbeMemPrettyPrint(pMem, zBuf);
+    char zBuf[1000];
-    fprintf(stderr, "INPUT:  %s\n", zBuf);
+    sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);  
+    sqlite3VdbeMemPrettyPrint(pMem, &acc);
+    fprintf(stderr, "INPUT:  %s\n", sqlite3StrAccumFinish(&acc));
   }
 #endif
 
@@ -325,9 +327,11 @@ SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
 translate_out:
 #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
   {
-    char zBuf[100];
+    StrAccum acc;
-    sqlite3VdbeMemPrettyPrint(pMem, zBuf);
+    char zBuf[1000];
-    fprintf(stderr, "OUTPUT: %s\n", zBuf);
+    sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);  
+    sqlite3VdbeMemPrettyPrint(pMem, &acc);
+    fprintf(stderr, "OUTPUT: %s\n", sqlite3StrAccumFinish(&acc));
   }
 #endif
   return SQLITE_OK;

src/vdbe.c

@@ -481,12 +481,9 @@ static u16 numericType(Mem *pMem){
 ** Write a nice string representation of the contents of cell pMem
 ** into buffer zBuf, length nBuf.
 */
-void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
+void sqlite3VdbeMemPrettyPrint(Mem *pMem, StrAccum *pStr){
-  char *zCsr = zBuf;
   int f = pMem->flags;
-
   static const char *const encnames[] = {"(X)", "(8)", "(16LE)", "(16BE)"};
-
   if( f&MEM_Blob ){
     int i;
     char c;
@@ -502,57 +499,40 @@ void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){
     }else{
       c = 's';
     }
-    *(zCsr++) = c;
+    sqlite3_str_appendf(pStr, "%cx", c);
-    *(zCsr++) = 'x';
-    sqlite3_snprintf(100, zCsr, "%d[", pMem->n);
-    zCsr += sqlite3Strlen30(zCsr);
     for(i=0; i<25 && i<pMem->n; i++){
-      sqlite3_snprintf(100, zCsr, "%02X", ((int)pMem->z[i] & 0xFF));
+      sqlite3_str_appendf(pStr, "%02X", ((int)pMem->z[i] & 0xFF));
-      zCsr += sqlite3Strlen30(zCsr);
     }
-    *zCsr++ = '|';
+    sqlite3_str_appendf(pStr, "|");
     for(i=0; i<25 && i<pMem->n; i++){
       char z = pMem->z[i];
-      if( z<32 || z>126 ) *zCsr++ = '.';
+      sqlite3_str_appendchar(pStr, 1, (z<32||z>126)?'.':z);
-      else *zCsr++ = z;
     }
-    *(zCsr++) = ']';
+    sqlite3_str_appendf(pStr,"]");
     if( f & MEM_Zero ){
-      sqlite3_snprintf(100, zCsr,"+%dz",pMem->u.nZero);
+      sqlite3_str_appendf(pStr, "+%dz",pMem->u.nZero);
-      zCsr += sqlite3Strlen30(zCsr);
     }
-    *zCsr = '\0';
   }else if( f & MEM_Str ){
-    int j, k;
+    int j;
-    zBuf[0] = ' ';
+    int c;
     if( f & MEM_Dyn ){
-      zBuf[1] = 'z';
+      c = 'z';
       assert( (f & (MEM_Static|MEM_Ephem))==0 );
     }else if( f & MEM_Static ){
-      zBuf[1] = 't';
+      c = 't';
       assert( (f & (MEM_Dyn|MEM_Ephem))==0 );
     }else if( f & MEM_Ephem ){
-      zBuf[1] = 'e';
+      c = 'e';
       assert( (f & (MEM_Static|MEM_Dyn))==0 );
     }else{
-      zBuf[1] = 's';
+      c = 's';
     }
-    k = 2;
+    sqlite3_str_appendf(pStr, " %c%d[", c, pMem->n);
-    sqlite3_snprintf(100, &zBuf[k], "%d", pMem->n);
-    k += sqlite3Strlen30(&zBuf[k]);
-    zBuf[k++] = '[';
     for(j=0; j<25 && j<pMem->n; j++){
       u8 c = pMem->z[j];
-      if( c>=0x20 && c<0x7f ){
+      sqlite3_str_appendchar(pStr, 1, (c>=0x20&&c<=0x7f) ? c : '.');
-        zBuf[k++] = c;
-      }else{
-        zBuf[k++] = '.';
-      }
     }
-    zBuf[k++] = ']';
+    sqlite3_str_appendf(pStr, "]%s", encnames[pMem->enc]);
-    sqlite3_snprintf(100,&zBuf[k], encnames[pMem->enc]);
-    k += sqlite3Strlen30(&zBuf[k]);
-    zBuf[k++] = 0;
   }
 }
 #endif
@@ -579,9 +559,11 @@ static void memTracePrint(Mem *p){
   }else if( sqlite3VdbeMemIsRowSet(p) ){
     printf(" (rowset)");
   }else{
-    char zBuf[200];
+    StrAccum acc;
-    sqlite3VdbeMemPrettyPrint(p, zBuf);
+    char zBuf[1000];
-    printf(" %s", zBuf);
+    sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
+    sqlite3VdbeMemPrettyPrint(p, &acc);
+    printf(" %s", sqlite3StrAccumFinish(&acc));
   }
   if( p->flags & MEM_Subtype ) printf(" subtype=0x%02x", p->eSubtype);
 }

src/vdbeInt.h

@@ -596,7 +596,7 @@ int sqlite3VdbeCheckFk(Vdbe *, int);
 
 #ifdef SQLITE_DEBUG
   void sqlite3VdbePrintSql(Vdbe*);
-  void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
+  void sqlite3VdbeMemPrettyPrint(Mem *pMem, StrAccum *pStr);
 #endif
 #ifndef SQLITE_OMIT_UTF16
   int sqlite3VdbeMemTranslate(Mem*, u8);