Both exist: I think they misquoted. Either way... Yes, it makes the sign not applicable.
http://www.statutes.legis.state.tx.us/Docs/PE/htm/PE.30.htm
Sec. 30.05. CRIMINAL TRESPASS. (a) A person commits an offense if the person enters or remains on or in property of another, including residential land, agricultural land, a recreational vehicle park, a building, or an aircraft or other vehicle, without effective consent and the person:
(1) had notice that the entry was forbidden; or
(2) received notice to depart but failed to do so.
(b) For purposes of this section:
(1) "Entry" means the intrusion of the entire body.
(2) "Notice" means:
(A) oral or written communication by the owner or someone with apparent authority to act for the owner;
(B) fencing or other enclosure obviously designed to exclude intruders or to contain livestock;
(C) a sign or signs posted on the property or at the entrance to the building, reasonably likely to come to the attention of intruders, indicating that entry is forbidden;
(D) the placement of identifying purple paint marks on trees or posts on the property, provided that the marks are:
(i) vertical lines of not less than eight inches in length and not less than one inch in width;
(ii) placed so that the bottom of the mark is not less than three feet from the ground or more than five feet from the ground; and
(iii) placed at locations that are readily visible to any person approaching the property and no more than:
(a) 100 feet apart on forest land; or
(b) 1,000 feet apart on land other than forest land; or
(E) the visible presence on the property of a crop grown for human consumption that is under cultivation, in the process of being harvested, or marketable if harvested at the time of entry.
(3) "Shelter center" has the meaning assigned by Section 51.002, Human Resources Code.
(4) "Forest land" means land on which the trees are potentially valuable for timber products.
(5) "Agricultural land" has the meaning assigned by Section 75.001, Civil Practice and Remedies Code.
30.06
sec. 30.06. TRESPASS BY HOLDER OF LICENSE TO CARRY CONCEALED HANDGUN. (a) A license holder commits an offense if the license holder: (1) carries a handgun under the authority of Subchapter H, Chapter 411, Government Code, on property of another without effective consent; and (2) received notice that: (A) entry on the property by a license holder with a concealed handgun was forbidden; or (B) remaining on the property with a concealed handgun was forbidden and failed to depart.