Add the SQLITE_DBCONFIG_RESET_DATABASE control as a replacement for

the reset_database pragma.  Resetting the database should be hard enough
to do that it cannot be done by accident.

FossilOrigin-Name: ff836cb8b0377c5970ecb2b797702e2b5d208eda443ecbd55f4c238a3094b28a

5 files changed, 51 insertions, 8 deletions

diff --git a/src/main.c b/src/main.c
index 442067a14..d23f9afcf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -834,6 +834,7 @@ int sqlite3_db_config(sqlite3 *db, int op, ...){
         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
         { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
+        { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
       };
       unsigned int i;
       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
diff --git a/src/pragma.h b/src/pragma.h
index a1695ff98..c9ece2dc8 100644
--- a/src/pragma.h
+++ b/src/pragma.h
@@ -506,11 +506,6 @@ static const PragmaName aPragmaName[] = {
   /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
- {/* zName:     */ "reset_database",
-  /* ePragTyp:  */ PragTyp_FLAG,
-  /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
-  /* ColNames:  */ 0, 0,
-  /* iArg:      */ SQLITE_WriteSchema|SQLITE_ResetDatabase },
  {/* zName:     */ "reverse_unordered_selects",
   /* ePragTyp:  */ PragTyp_FLAG,
   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,
@@ -651,4 +646,4 @@ static const PragmaName aPragmaName[] = {
   /* iArg:      */ SQLITE_WriteSchema },
 #endif
 };
-/* Number of pragmas: 61 on by default, 78 total. */
+/* Number of pragmas: 60 on by default, 77 total. */
diff --git a/src/shell.c.in b/src/shell.c.in
index c0e5c7a75..e759921ab 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -3340,6 +3340,7 @@ static char zHelp[] =
   ".check GLOB            Fail if output since .testcase does not match\n"
   ".clone NEWDB           Clone data into NEWDB from the existing database\n"
   ".databases             List names and files of attached databases\n"
+  ".dbconfig ?op? ?val?   List or change sqlite3_db_config() options\n"
   ".dbinfo ?DB?           Show status information about the database\n"
   ".dump ?TABLE? ...      Dump the database in an SQL text format\n"
   "                         If TABLE specified, only dump tables matching\n"
@@ -5782,7 +5783,35 @@ static int do_meta_command(char *zLine, ShellState *p){
     }
   }else
 
-  if( c=='d' && strncmp(azArg[0], "dbinfo", n)==0 ){
+  if( c=='d' && n>=3 && strncmp(azArg[0], "dbconfig", n)==0 ){
+    static const struct DbConfigChoices {const char *zName; int op;} aDbConfig[] = {
+        { "enable_fkey",      SQLITE_DBCONFIG_ENABLE_FKEY            },
+        { "enable_trigger",   SQLITE_DBCONFIG_ENABLE_TRIGGER         },
+        { "fts3_tokenizer",   SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER  },
+        { "load_extension",   SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION  },
+        { "no_ckpt_on_close", SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE       },
+        { "enable_qpsg",      SQLITE_DBCONFIG_ENABLE_QPSG            },
+        { "trigger_eqp",      SQLITE_DBCONFIG_TRIGGER_EQP            },
+        { "reset_database",   SQLITE_DBCONFIG_RESET_DATABASE         },
+    };
+    int ii, v;
+    open_db(p, 0);
+    for(ii=0; ii<ArraySize(aDbConfig); ii++){
+      if( nArg>1 && strcmp(azArg[1], aDbConfig[ii].zName)!=0 ) continue;
+      if( nArg>=3 ){
+        sqlite3_db_config(p->db, aDbConfig[ii].op, booleanValue(azArg[2]), 0);
+      }
+      sqlite3_db_config(p->db, aDbConfig[ii].op, -1, &v);
+      utf8_printf(p->out, "%18s %s\n", aDbConfig[ii].zName, v ? "on" : "off");
+      if( nArg>1 ) break;
+    }
+    if( nArg>1 && ii==ArraySize(aDbConfig) ){
+      utf8_printf(stderr, "Error: unknown dbconfig \"%s\"\n", azArg[1]);
+      utf8_printf(stderr, "Enter \".dbconfig\" with no arguments for a list\n");
+    }   
+  }else
+
+  if( c=='d' && n>=3 && strncmp(azArg[0], "dbinfo", n)==0 ){
     rc = shell_dbinfo_command(p, nArg, azArg);
   }else
 
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 877528c68..696b3cb2d 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -2112,6 +2112,21 @@ struct sqlite3_mem_methods {
 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 
 ** it is not disabled, 1 if it is.  
 ** </dd>
+**
+** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
+** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
+** [VACUUM] in order to reset a database back to an empty database
+** with no schema and no content. The following process works even for
+** a badly corrupted database file:
+** <ol>
+** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
+** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
+** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
+** </ol>
+** Because resetting a database is destructive and irreversible, the
+** process requires the use of this obscure API and multiple steps to help
+** ensure that it does not happen by accident.
+** </dd>
 ** </dl>
 */
 #define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
@@ -2123,7 +2138,8 @@ struct sqlite3_mem_methods {
 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
 #define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
 #define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
-#define SQLITE_DBCONFIG_MAX                   1008 /* Largest DBCONFIG */
+#define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
+#define SQLITE_DBCONFIG_MAX                   1009 /* Largest DBCONFIG */
 
 /*
 ** CAPI3REF: Enable Or Disable Extended Result Codes
diff --git a/src/test1.c b/src/test1.c
index 0f139ceba..f2511d259 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -7418,6 +7418,8 @@ static int SQLITE_TCLAPI test_sqlite3_db_config(
     { "LOAD_EXTENSION",  SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
     { "NO_CKPT_ON_CLOSE",SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE },
     { "QPSG",            SQLITE_DBCONFIG_ENABLE_QPSG },
+    { "TRIGGER_EQP",     SQLITE_DBCONFIG_TRIGGER_EQP },
+    { "RESET_DB",        SQLITE_DBCONFIG_RESET_DATABASE },
   };
   int i;
   int v;