updated for version 7.3.879
Problem:    When using an ex command in operator pending mode, using Esc to
            abort the command still executes the operator. (David Bürgin)
Solution:   Clear the operator when the ex command fails. (Christian Brabandt)
diff --git a/src/normal.c b/src/normal.c
index d6c0abb..181dbcb 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -5418,6 +5418,7 @@
     cmdarg_T  *cap;
 {
     int	    old_p_im;
+    int	    cmd_result;
 
 #ifdef FEAT_VISUAL
     if (VIsual_active)
@@ -5449,7 +5450,7 @@
 	old_p_im = p_im;
 
 	/* get a command line and execute it */
-	do_cmdline(NULL, getexline, NULL,
+	cmd_result = do_cmdline(NULL, getexline, NULL,
 			    cap->oap->op_type != OP_NOP ? DOCMD_KEEPLINE : 0);
 
 	/* If 'insertmode' changed, enter or exit Insert mode */
@@ -5461,12 +5462,17 @@
 		restart_edit = 0;
 	}
 
-	/* The start of the operator may have become invalid by the Ex
-	 * command. */
-	if (cap->oap->op_type != OP_NOP
+	if (cmd_result == FAIL)
+	    /* The Ex command failed, do not execute the operator. */
+	    clearop(cap->oap);
+	else if (cap->oap->op_type != OP_NOP
 		&& (cap->oap->start.lnum > curbuf->b_ml.ml_line_count
 		    || cap->oap->start.col >
-			       (colnr_T)STRLEN(ml_get(cap->oap->start.lnum))))
+			       (colnr_T)STRLEN(ml_get(cap->oap->start.lnum))
+		    || did_emsg
+		    ))
+	    /* The start of the operator has become invalid by the Ex command.
+	     */
 	    clearopbeep(cap->oap);
     }
 }
diff --git a/src/version.c b/src/version.c
index 8d3839a..db39c93 100644
--- a/src/version.c
+++ b/src/version.c
@@ -729,6 +729,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    879,
+/**/
     878,
 /**/
     877,