Bug #57276 mysqltest: add support for simple compares in if/while conditions

      Added more parsing in do_block()
      Limitation: left operand must be variable
      Also changed var_set_int from 57036 to var_check_int
      Added tests to mysqltest.test
      Some tests can now be simplified but will take this later
      Updated after comments, now white space around operator not needed

client/mysqltest.cc

@@ -482,7 +482,8 @@ VAR* var_init(VAR* v, const char *name, int name_len, const char *val,
               int val_len);
 VAR* var_get(const char *var_name, const char** var_name_end,
              my_bool raw, my_bool ignore_not_existing);
-void eval_expr(VAR* v, const char *p, const char** p_end);
+void eval_expr(VAR* v, const char *p, const char** p_end,
+               bool open_end=false);
 my_bool match_delimiter(int c, const char *delim, uint length);
 void dump_result_to_reject_file(char *buf, int size);
 void dump_warning_messages();
@@ -2040,9 +2041,11 @@ static void var_free(void *v)
 
 C_MODE_END
 
-void var_set_int(VAR *v, const char *str)
+void var_check_int(VAR *v)
 {
   char *endptr;
+  char *str= v->str_val;
+  
   /* Initially assume not a number */
   v->int_val= 0;
   v->is_int= false;
@@ -2089,7 +2092,7 @@ VAR *var_init(VAR *v, const char *name, int name_len, const char *val,
     memcpy(tmp_var->str_val, val, val_len);
     tmp_var->str_val[val_len]= 0;
   }
-  var_set_int(tmp_var, val);
+  var_check_int(tmp_var);
   tmp_var->name_len = name_len;
   tmp_var->str_val_len = val_len;
   tmp_var->alloced_len = val_alloc_len;
@@ -2540,7 +2543,7 @@ void var_copy(VAR *dest, VAR *src)
 }
 
 
-void eval_expr(VAR *v, const char *p, const char **p_end)
+void eval_expr(VAR *v, const char *p, const char **p_end, bool open_end)
 {
 
   DBUG_ENTER("eval_expr");
@@ -2558,7 +2561,7 @@ void eval_expr(VAR *v, const char *p, const char **p_end)
 
     /* Make sure there was just a $variable and nothing else */
     const char* end= *p_end + 1;
-    if (end < expected_end)
+    if (end < expected_end && !open_end)
       die("Found junk '%.*s' after $variable in expression",
           (int)(expected_end - end - 1), end);
 
@@ -2605,7 +2608,7 @@ void eval_expr(VAR *v, const char *p, const char **p_end)
     v->str_val_len = new_val_len;
     memcpy(v->str_val, p, new_val_len);
     v->str_val[new_val_len] = 0;
-    var_set_int(v, p);
+    var_check_int(v);
   }
   DBUG_VOID_RETURN;
 }
@@ -5498,6 +5501,40 @@ int do_done(struct st_command *command)
   return 0;
 }
 
+/* Operands available in if or while conditions */
+
+enum block_op {
+  EQ_OP,
+  NE_OP,
+  GT_OP,
+  GE_OP,
+  LT_OP,
+  LE_OP,
+  ILLEG_OP
+};
+
+
+enum block_op find_operand(const char *start)
+{
+ char first= *start;
+ char next= *(start+1);
+ 
+ if (first == '=' && next == '=')
+   return EQ_OP;
+ if (first == '!' && next == '=')
+   return NE_OP;
+ if (first == '>' && next == '=')
+   return GE_OP;
+ if (first == '>')
+   return GT_OP;
+ if (first == '<' && next == '=')
+   return LE_OP;
+ if (first == '<')
+   return LT_OP;
+ 
+ return ILLEG_OP;
+}
+
 
 /*
   Process start of a "if" or "while" statement
@@ -5523,6 +5560,13 @@ int do_done(struct st_command *command)
   A '!' can be used before the <expr> to indicate it should
   be executed if it evaluates to zero.
 
+  <expr> can also be a simple comparison condition:
+
+  <variable> <op> <expr>
+
+  The left hand side must be a variable, the right hand side can be a
+  variable, number, string or `query`. Operands are ==, !=, <, <=, >, >=.
+  == and != can be used for strings, all can be used for numerical values.
 */
 
 void do_block(enum block_cmd cmd, struct st_command* command)
@@ -5558,6 +5602,9 @@ void do_block(enum block_cmd cmd, struct st_command* command)
   if (!expr_start++)
     die("missing '(' in %s", cmd_name);
 
+  while (my_isspace(charset_info, *expr_start))
+    expr_start++;
+  
   /* Check for !<expr> */
   if (*expr_start == '!')
   {
@@ -5576,14 +5623,94 @@ void do_block(enum block_cmd cmd, struct st_command* command)
     die("Missing '{' after %s. Found \"%s\"", cmd_name, p);
 
   var_init(&v,0,0,0,0);
-  eval_expr(&v, expr_start, &expr_end);
 
+  /* If expression starts with a variable, it may be a compare condition */
+
+  if (*expr_start == '$')
+  {
+    const char *curr_ptr= expr_end;
+    eval_expr(&v, expr_start, &curr_ptr, true);
+    while (my_isspace(charset_info, *++curr_ptr))
+    {}
+    /* If there was nothing past the variable, skip condition part */
+    if (curr_ptr == expr_end)
+      goto NO_COMPARE;
+
+    enum block_op operand= find_operand(curr_ptr);
+    if (operand == ILLEG_OP)
+      die("Found junk '%.*s' after $variable in condition",
+          (int)(expr_end - curr_ptr), curr_ptr);
+
+    /* We could silently allow this, but may be confusing */
+    if (not_expr)
+      die("Negation and comparison should not be combined, please rewrite");
+    
+    /* Skip the 1 or 2 chars of the operand, then white space */
+    if (operand == LT_OP || operand == GT_OP)
+    {
+      curr_ptr++;
+    }
+    else
+    {
+      curr_ptr+= 2;
+    }
+    while (my_isspace(charset_info, *curr_ptr))
+      curr_ptr++;
+
+    VAR v2;
+    var_init(&v2,0,0,0,0);
+    eval_expr(&v2, curr_ptr, &expr_end);
+
+    if ((operand!=EQ_OP && operand!=NE_OP) && ! (v.is_int && v2.is_int))
+      die ("Only == and != are supported for string values");
+
+    /* Now we overwrite the first variable with 0 or 1 (for false or true) */
+
+    switch (operand)
+    {
+    case EQ_OP:
+      if (v.is_int)
+        v.int_val= (v2.is_int && v2.int_val == v.int_val);
+      else
+        v.int_val= !strcmp (v.str_val, v2.str_val);
+      break;
+      
+    case NE_OP:
+      if (v.is_int)
+        v.int_val= ! (v2.is_int && v2.int_val == v.int_val);
+      else
+        v.int_val= (strcmp (v.str_val, v2.str_val) != 0);
+      break;
+
+    case LT_OP:
+      v.int_val= (v.int_val < v2.int_val);
+      break;
+    case LE_OP:
+      v.int_val= (v.int_val <= v2.int_val);
+      break;
+    case GT_OP:
+      v.int_val= (v.int_val > v2.int_val);
+      break;
+    case GE_OP:
+      v.int_val= (v.int_val >= v2.int_val);
+      break;
+    }
+
+    v.is_int= TRUE;
+  } else
+  {
+    if (*expr_start != '`' && ! my_isdigit(charset_info, *expr_start))
+      die("Expression in if/while must beging with $, ` or a number");
+    eval_expr(&v, expr_start, &expr_end);
+  }
+
+ NO_COMPARE:
   /* Define inner block */
   cur_block++;
   cur_block->cmd= cmd;
-  if (v.int_val)
+  if (v.is_int)
   {
-    cur_block->ok= TRUE;
+    cur_block->ok= (v.int_val != 0);
   } else
   /* Any non-empty string which does not begin with 0 is also TRUE */
   {

mysql-test/r/mysqltest.result

@@ -401,8 +401,36 @@ true-outer
 Counter is greater than 0, (counter=10)
 Counter is not 0, (counter=0)
 Counter is true, (counter=alpha)
-Beta is true
 while with string, only once
+5<7
+5<7 again
+5<7 still
+5<6
+5>=5
+5>=5 again
+5>3
+5==5
+5!=8
+5!=five
+5==3+2
+5   ==   5
+hello == hello
+hello   ==   hello
+hello != goodbye
+two words
+two words are two words
+right answer
+anything goes
+0 != string
+mysqltest: At line 2: Only == and != are supported for string values
+mysqltest: At line 2: Found junk '~= 6' after $variable in condition
+mysqltest: At line 2: Expression in if/while must beging with $, ` or a number
+counter is 2
+counter is 3
+counter is 4
+counter is 5
+counter is 6
+counter is 7
 1
 Testing while with not
 mysqltest: In included file "MYSQLTEST_VARDIR/tmp/mysqltest_while.inc": At line 64: Nesting too deeply
@@ -807,8 +835,6 @@ dir-list.txt
 SELECT 'c:\\a.txt' AS col;
 col
 z
-hej
-mysqltest: At line 1: Found junk ' != 143' after $variable in expression
 select 1;
 1
 1

mysql-test/t/mysqltest.test

@@ -1163,10 +1163,11 @@ if ($counter)
 {
   echo oops, -0 is true;
 }
-if (beta)
-{
-  echo Beta is true;
-}
+# This is no longer allowed, as a precaution against mistyped conditionals
+# if (beta)
+# {
+#   echo Beta is true;
+# }
 let $counter=gamma;
 while ($counter)
 {
@@ -1174,6 +1175,179 @@ while ($counter)
   let $counter=000;
 }
 
+# ----------------------------------------------------------------------------
+# Test if with compare conditions
+# ----------------------------------------------------------------------------
+
+let $ifvar= 5;
+let $ifvar2= 6;
+
+if ($ifvar < 7)
+{
+  echo 5<7;
+}
+if ($ifvar< 7)
+{
+  echo 5<7 again;
+}
+if ($ifvar<7)
+{
+  echo 5<7 still;
+}
+if ($ifvar < $ifvar2)
+{
+  echo 5<6;
+}
+if ($ifvar <= 4)
+{
+  echo 5<=4;
+}
+if ($ifvar >= 5)
+{
+  echo 5>=5;
+}
+if ($ifvar>=5)
+{
+  echo 5>=5 again;
+}
+if ($ifvar > 3)
+{
+  echo 5>3;
+}
+if ($ifvar == 4)
+{
+  echo 5==4;
+}
+if ($ifvar == 5)
+{
+  echo 5==5;
+}
+if ($ifvar != 8)
+{
+  echo 5!=8;
+}
+# Any number should compare unequal to any string
+if ($ifvar != five)
+{
+  echo 5!=five;
+}
+if ($ifvar == `SELECT 3+2`)
+{
+  echo 5==3+2;
+}
+if ($ifvar    ==       5)
+{
+  echo 5   ==   5;
+}
+let $ifvar= hello;
+if ($ifvar == hello there)
+{
+  echo hello == hello there;
+}
+if ($ifvar == hello)
+{
+  echo hello == hello;
+}
+if ($ifvar == hell)
+{
+  echo hello == hell;
+}
+if ($ifvar    ==    hello)
+{
+  echo hello   ==   hello;
+}
+if ($ifvar != goodbye)
+{
+  echo hello != goodbye;
+}
+
+let $ifvar= two words;
+if ($ifvar == two words)
+{
+  echo two words;
+}
+if ($ifvar == `SELECT 'two words'`)
+{
+  echo two words are two words;
+}
+if (42)
+{
+  echo right answer;
+}
+if (0)
+{
+  echo wrong answer;
+}
+# Non-empty string treated as 'true'
+if (`SELECT 'something'`)
+{
+  echo anything goes;
+}
+# Make sure 0 and string compare right
+let $ifvar= 0;
+if ($ifvar == string)
+{
+  echo 0 == string;
+}
+if ($ifvar != string)
+{
+  echo 0 != string;
+}
+--write_file $MYSQL_TMP_DIR/mysqltest.sql
+let $var= 5;
+if ($var >= four)
+{
+ echo 5>=four;
+}
+EOF
+--error 1
+--exec $MYSQL_TEST < $MYSQL_TMP_DIR/mysqltest.sql 2>&1
+remove_file $MYSQL_TMP_DIR/mysqltest.sql;
+
+--write_file $MYSQL_TMP_DIR/mysqltest.sql
+let $var= 5;
+if ($var ~= 6)
+{
+ echo 5~=6;
+}
+EOF
+--error 1
+--exec $MYSQL_TEST < $MYSQL_TMP_DIR/mysqltest.sql 2>&1
+remove_file $MYSQL_TMP_DIR/mysqltest.sql;
+
+--write_file $MYSQL_TMP_DIR/mysqltest.sql
+let $var= text;
+if (var == text)
+{
+ echo Oops I forgot the $;
+}
+EOF
+--error 1
+--exec $MYSQL_TEST < $MYSQL_TMP_DIR/mysqltest.sql 2>&1
+remove_file $MYSQL_TMP_DIR/mysqltest.sql;
+
+# ----------------------------------------------------------------------------
+# Test while with compare conditions
+# ----------------------------------------------------------------------------
+
+let $counter= 2;
+
+while ($counter < 5)
+{
+  echo counter is $counter;
+  inc $counter;
+}
+let $ifvar=;
+while ($ifvar != stop)
+{
+  if ($counter >= 7)
+  {
+    let $ifvar= stop;
+  }
+  echo counter is $counter;
+  inc $counter;
+}
+
 # ----------------------------------------------------------------------------
 # Test while, { and }
 # ----------------------------------------------------------------------------
@@ -2529,26 +2703,6 @@ rmdir $MYSQLTEST_VARDIR/tmp/testdir;
 --replace_result c:\\a.txt z
 SELECT 'c:\\a.txt' AS col;
 
-#
-# Bug#32307 mysqltest - does not detect illegal if syntax
-#
-
-let $test= 1;
-if ($test){
-  echo hej;
-}
-
---write_file $MYSQLTEST_VARDIR/tmp/mysqltest.sql
-if ($mysql_errno != 1436)
-{
- echo ^ Should not be allowed!
-}
-EOF
---error 1
---exec $MYSQL_TEST < $MYSQLTEST_VARDIR/tmp/mysqltest.sql 2>&1
-remove_file $MYSQLTEST_VARDIR/tmp/mysqltest.sql;
-
-
 # ----------------------------------------------------------------------------
 # Test that -- is not allowed as comment, only as mysqltest builtin command
 # ----------------------------------------------------------------------------