Improved auto-detection of EXPLAIN output in the shell.

FossilOrigin-Name: 6c6d7a6e89e67cdb0813d3eebb869aafb43d43ed

manifest

@@ -1,5 +1,5 @@
-C Add\sauto-explain\smode\sto\sthe\scommand-line\sshell.\s\sDefault\son.\s\sAuto-explain\ntries\sto\sautomatically\sdetect\sEXPLAIN\squeries\sand\sformat\sthem\sappropriately.
+C Improved\sauto-detection\sof\sEXPLAIN\soutput\sin\sthe\sshell.
-D 2016-02-09T18:39:25.001
+D 2016-02-09T20:04:07.701
 F Makefile.in 95ea52e9c02962e31f986fe8ea5805104c84f94b
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 0fe3b22f8e29bcde0533ada7957a5f15835d797a
@@ -349,7 +349,7 @@ F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c 9f7ce3a3c087afb7597b7c916c99126ff3f12f0c
 F src/rowset.c 9fe4b3ad7cc00944386bb600233d8f523de07a6e
 F src/select.c ff80004a9a6ece891a8d9327a88e7b6e2588ee6d
-F src/shell.c eae68d3a7aff0f4195074d5f204dc2c219e748fd
+F src/shell.c dad82078194d5dae39d35f131e4b60dd3276ab27
 F src/sqlite.h.in cf22ad1d52dca2c9862d63833e581028119aab7e
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h dfbe62ffd95b99afe2140d8c35b180d11924072d
@@ -1427,10 +1427,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 51b6823f4c9376d549f572f5a33cac1e4c9783a2
+P 1d62aa6b315df47cafb33da7ca79d3386a2fdd48
-R 38fbc467636eda7f2b73a6fc60969ca8
+R 7efe35d4fa73e934642e7f03926fba5a
-T *branch * auto-explain
-T *sym-auto-explain *
-T -sym-trunk *
 U drh
-Z 2feb45f9e3784b1a58bde6f86e718a1d
+Z d64951a4b1ff916463dbab9f9acfa416

manifest.uuid

@@ -1 +1 @@
-1d62aa6b315df47cafb33da7ca79d3386a2fdd48
+6c6d7a6e89e67cdb0813d3eebb869aafb43d43ed

src/shell.c

@@ -1506,10 +1506,17 @@ static void explain_data_prepare(ShellState *p, sqlite3_stmt *pSql){
 
   /* Try to figure out if this is really an EXPLAIN statement. If this
   ** cannot be verified, return early.  */
+  if( sqlite3_column_count(pSql)!=8 ){
+    p->cMode = p->mode;
+    return;
+  }
   zSql = sqlite3_sql(pSql);
   if( zSql==0 ) return;
   for(z=zSql; *z==' ' || *z=='\t' || *z=='\n' || *z=='\f' || *z=='\r'; z++);
-  if( sqlite3_strnicmp(z, "explain", 7) ) return;
+  if( sqlite3_strnicmp(z, "explain", 7) ){
+    p->cMode = p->mode;
+    return;
+  }
 
   for(iOp=0; SQLITE_ROW==sqlite3_step(pSql); iOp++){
     int i;
@@ -1526,6 +1533,20 @@ static void explain_data_prepare(ShellState *p, sqlite3_stmt *pSql){
 
     /* Grow the p->aiIndent array as required */
     if( iOp>=nAlloc ){
+      if( iOp==0 ){
+        /* Do further verfication that this is explain output.  Abort if
+        ** it is not */
+        static const char *explainCols[] = {
+           "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment" };
+        int jj;
+        for(jj=0; jj<ArraySize(explainCols); jj++){
+          if( strcmp(sqlite3_column_name(pSql,jj),explainCols[jj])!=0 ){
+            p->cMode = p->mode;
+            sqlite3_reset(pSql);
+            return;
+          }
+        }
+      }
       nAlloc += 100;
       p->aiIndent = (int*)sqlite3_realloc64(p->aiIndent, nAlloc*sizeof(int));
       abYield = (int*)sqlite3_realloc64(abYield, nAlloc*sizeof(int));
@@ -1631,9 +1652,9 @@ static int shell_exec(
 
       if( pArg ){
         pArg->cMode = pArg->mode;
-        if( sqlite3_column_count(pStmt)==8
+        if( pArg->autoExplain
+         && sqlite3_column_count(pStmt)==8
          && sqlite3_strlike("%EXPLAIN%", sqlite3_sql(pStmt),0)==0
-         && sqlite3_strlike("%QUERY%", sqlite3_sql(pStmt),0)!=0
         ){
           pArg->cMode = MODE_Explain;
         }