ios: using the same sqlite parameter more than once causes premature memory deallocation

Question

Note: the question is misleading.. i thought it was using more than one parameter that causes a memory error.. but that\'s not the reason.. the reason was an i

Answer 1

I finally found it! after chasing so many red herrings.. the best advice i got was on a forum specialized for sqlite: the point was to keep the guts of sqlite out of my debugging reach, it's extremely unlikely that it's sqlite's fault.

i basically decided to break my sql statement into smaller pieces and run each on it's own:

original sql statement that caused the memory problem:

    NSString* updateStmt = @"INSERT INTO search_email(docid, meta, subject, body, sender, tos, ccs, folder, threadid)"
    " SELECT ?, ?, ?, ?, ?, ?, ?, ?,"
    " coalesce((SELECT search_email.threadID "
    " FROM search_email "
    " WHERE search_email.subject MATCH ?  UNION SELECT * FROM "
    " (SELECT threadID FROM  (SELECT threadID FROM search_email WHERE search_email.sender MATCH ? "
    " INTERSECT SELECT threadID FROM search_email WHERE search_email.tos MATCH ? ) "
    "  UNION "
    " SELECT threadID FROM (SELECT threadID FROM search_email WHERE search_email.sender MATCH ? "
    "       INTERSECT SELECT threadID FROM search_email WHERE search_email.tos MATCH ?)) "
    " LIMIT 1"
    " ),"
    " ?"
    " )";

the problem happened whenever i supplied strings with special characters to match.. the following are examples of problematic parameters sent to MATCH:

sabaho :)
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so to go around that i simply replaced MATCH with a normal = comparison.. but cleaned up the parameter using regex first:

NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"re:(\\s)*"
                                                                       options:NSRegularExpressionCaseInsensitive
                                                                         error:&error];


                            error:&error];

NSString *filteredSubjectFromRe = [regex stringByReplacingMatchesInString:subject
                                                                  options:0
                                                                    range:NSMakeRange(0, [subject length])
                                                             withTemplate:@""];

if(searchEmailInsertStmt == nil) {

    NSString* updateStmt = @"INSERT INTO search_email(docid, meta, subject, body, sender, tos, ccs, folder, threadid)"
    " SELECT ?, ?, ?, ?, ?, ?, ?, ?,"
    " coalesce((SELECT search_email.threadID "
    " FROM search_email "
    " WHERE search_email.subject = ? UNION SELECT * FROM "
    " (SELECT threadID FROM  (SELECT threadID FROM search_email WHERE search_email.sender = ? "
    " INTERSECT SELECT threadID FROM search_email WHERE search_email.tos = ? ) "
    "  UNION "
    " SELECT threadID FROM (SELECT threadID FROM search_email WHERE search_email.sender = ? "
    "       INTERSECT SELECT threadID FROM search_email WHERE search_email.tos = ?)) "
    " LIMIT 1"
    " ),"
    " ?"
    " )";