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

1 files changed, 136 insertions, 9 deletions

diff --git a/client/mysqltest.cc b/client/mysqltest.cc
index 1afed9fa310..1cc275a37be 100644
--- a/client/mysqltest.cc
+++ b/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 */
   {