Christopher Coakley, 30, with an address at Empress Place, in north inner-city Dublin, was found guilty of being intoxicated to the extent of being a danger to himself and others and using insulting, threatening or abusive words or behaviour.
He was cleared of criminal damage to a garda van by spitting.
Judge Bryan Smyth heard at Dublin District Court that gardai were called to an apartment in the capital on a date in 2020.
Mr Coakley, who claimed he was invited there, was asleep when gardai were called to put him out.
Garda Kevin Marron alleged Coakley was "quite clearly intoxicated", very agitated and "started verbally abusing myself".
He maintained that the accused was spitting when he was put into a Garda van.
There was spit on the van floor when it arrived at the Garda station.
Coakley, already serving an eight-year sentence for other crimes, told the court it was a lie.
He contended he was woken up in the apartment by other gardai, and claimed they were "lashing me out of it" with batons.
Asked was he abusive outside to Garda Marron, he denied spitting but said he might have been roaring as a result of what he claimed happened earlier.
Cross-examined, he told the court that he had been out for the previous two days.
He had drink taken and admitted, "there would have been cocaine taken, a small bit of cocaine".
Defence solicitor Yvonne Bambury said he had been irate and that may have caused a projectile, but the spitting was not intentional, and she submitted that Coakley was not charged with assault.
Garda Marron said the accused had been on a "two-day bender of alcohol and cocaine", and he had 121 prior criminal convictions.
His past offences included burglary, theft and robbery.
The court heard he is serving an eight-year sentence imposed by Dublin Circuit Criminal Court last year for robbery and attempted robbery.
His solicitor said he came from a good family. But he had a drug abuse problem, went through juvenile detention centres and later was "in and out of prison".
However, he was seeking help for addiction issues.
Judge Smyth imposed a two-month sentence concurrent to his current prison term.
Coakley, who has over 100 previous convictions, previously served a six-year term for an armed robbery imposed in December 2015, and a three-year term for a hijacking in 2012 imposed in July 2015.
That case heard that he hijacked the car of a woman with her child on the back seat.
Another case in which he received no extra jail time heard that he hijacked a nurse's car during a drug-induced psychosis in the early hours of the morning near Temple Street Hospital and then reversed the car "like a mad man" with no lights on in April 2015.
He has spent more than half his life in institutions after leaving school following national school and has been a heroin addict since he was 13.
In February 2021, Coakley was hospitalised after suffering severe injuries after he was accused of stealing a boy’s bicycle.
Coakley suffered a broken jaw and a broken arm as well as other injuries when he was assaulted with another bicycle in the incident which unfolded in the Sherriff Street area of the capital.
In another assault, after Coakley was released from jail in 2020, he was the subject of a brutal assault from his former associates in the Hutch mob.
On that occasion, Coakley was targeted after he posed for photos in Mountjoy Prison with members of the rival Kinahan cartel, the mob who were responsible for murdering his cousin Derek Coakley Hutch in January, 2018, in a case that has yet to be solved.