fixed BSONElement::simpleRegex and changed return to a string. this fixes SERVER-239

4 files changed, 23 insertions, 13 deletions

diff --git a/db/jsobj.cpp b/db/jsobj.cpp
index f6153509432..9c823dae7f9 100644
--- a/db/jsobj.cpp
+++ b/db/jsobj.cpp
@@ -532,20 +532,27 @@ namespace mongo {
         return -1;
     }
 
-    const char *BSONElement::simpleRegex() const {
+    string BSONElement::simpleRegex() const {
         if ( *regexFlags() )                                                                     
-            return 0;                                                                              
+            return "";
+        
         const char *i = regex();                                                                 
         if ( *i != '^' )                                                                           
-            return 0;                                                                              
-        ++i;                                                                                       
+            return "";
+        ++i;       
         // Empty string matches everything, won't limit our search.                                
         if ( !*i )                                                                                 
-            return 0;                                                                              
-        for( ; *i; ++i )                                                                           
-            if (!( *i == ' ' || (*i>='0'&&*i<='9') || (*i>='@'&&*i<='Z') || (*i>='a'&&*i<='z') ))  
-                return 0;                                                                          
-        return regex() + 1;              
+            return 0;                      
+        
+        stringstream ss;
+        for( ; *i; ++i ){
+            if ( *i == ' ' || (*i>='0'&&*i<='9') || (*i>='@'&&*i<='Z') || (*i>='a'&&*i<='z') )
+                ss << *i;
+            else
+                break;
+        } 
+        
+        return ss.str();
     }    
 
     void BSONElement::validate() const {
diff --git a/db/jsobj.h b/db/jsobj.h
index c3d87c83ff3..1d07665337b 100644
--- a/db/jsobj.h
+++ b/db/jsobj.h
@@ -429,7 +429,10 @@ namespace mongo {
             assert(type() == RegEx);
             return value();
         }
-        const char *simpleRegex() const;
+
+        /** returns a regex that when used as a matcher, would return a super set of regex() */
+        string simpleRegex() const;
+
         /** Retrieve the regex flags (options) for a Regex element */
         const char *regexFlags() const {
             const char *p = regex();
diff --git a/db/queryutil.cpp b/db/queryutil.cpp
index 501de5f4f2d..48c2e03bf8c 100644
--- a/db/queryutil.cpp
+++ b/db/queryutil.cpp
@@ -32,8 +32,8 @@ namespace mongo {
         if ( e.eoo() )
             return;
         if ( e.type() == RegEx ) {
-            const char *r = e.simpleRegex();
-            if ( r ) {
+            const string r = e.simpleRegex();
+            if ( r.size() ) {
                 lower() = addObj( BSON( "" << r ) ).firstElement();
                 upper() = addObj( BSON( "" << simpleRegexEnd( r ) ) ).firstElement();
                 upperInclusive() = false;
diff --git a/jstests/regex3.js b/jstests/regex3.js
index 17d0cdbba82..5fb9810aeac 100644
--- a/jstests/regex3.js
+++ b/jstests/regex3.js
@@ -11,4 +11,4 @@ assert.eq( 2 , t.find( { name : /^e.*/ } ).count() , "no index count" );
 assert.eq( 4 , t.find( { name : /^e.*/ } ).explain().nscanned , "no index explain" );
 t.ensureIndex( { name : 1 } );
 assert.eq( 2 , t.find( { name : /^e.*/ } ).count() , "index count" );
-//assert.eq( 2 , t.find( { name : /^e.*/ } ).explain().nscanned , "index explain" ); // SERVER-239
+assert.eq( 2 , t.find( { name : /^e.*/ } ).explain().nscanned , "index explain" ); // SERVER-239