Dignitatis Humanæ color-coded with Quanta Cura and the Syllabus of Errors

[Geremia]

Color coded or bolded where Vatican II matches up with condemned propositions of Bl. Pius IX and Pope Gregory XVI. Compare Dignitatis Humanæ:

2. This Vatican Council declares that the human person has a right to religious freedom. This freedom means that all men are to be immune from coercion on the part of individuals or of social groups and of any human power, in such wise that no one is to be forced to act in a manner contrary to his own beliefs, whether privately or publicly, whether alone or in association with others, within due limits.
...
This right of the human person to religious freedom is to be recognized in the constitutional law whereby society is governed and thus it is to become a civil right.

to Bl. Pius IX's Quanta Cura:

For you well know, venerable brethren, that at this time men are found not a few who, applying to civil society the impious and absurd principle of "naturalism," as they call it, dare to teach that "the best constitution of public society and (also) civil progress altogether require that human society be conducted and governed without regard being had to religion any more than if it did not exist; or, at least, without any distinction being made between the true religion and false ones." And, against the doctrine of Scripture, of the Church, and of the Holy Fathers, they do not hesitate to assert that "that is the best condition of civil society, in which no duty is recognized, as attached to the civil power, of restraining by enacted penalties, offenders against the Catholic religion, except so far as public peace may require." From which totally false idea of social government they do not fear to foster that erroneous opinion, most fatal in its effects on the Catholic Church and the salvation of souls, called by Our Predecessor, Gregory XVI, an "insanity,"² viz., that "liberty of conscience and worship is each man's personal right, which ought to be legally proclaimed and asserted in every rightly constituted society; and that a right resides in the citizens to an absolute liberty, which should be restrained by no authority whether ecclesiastical or civil, whereby they may be able openly and publicly to manifest and declare any of their ideas whatever, either by word of mouth, by the press, or in any other way." But, while they rashly affirm this, they do not think and consider that they are preaching "liberty of perdition;"³ and that "if human arguments are always allowed free room for discussion, there will never be wanting men who will dare to resist truth, and to trust in the flowing speech of human wisdom; whereas we know, from the very teaching of our Lord Jesus Christ, how carefully Christian faith and wisdom should avoid this most injurious babbling."⁴

and to his Syllabus of Errors, which condemned the following:

15. Every man is free to embrace and profess that religion which, guided by the light of reason, he shall consider true.—Allocution "Maxima quidem," June 9, 1862; Damnatio "Multiplices inter," June 10, 1851.
  ...
  X. ERRORS HAVING REFERENCE TO MODERN LIBERALISM
  77. In the present day it is no longer expedient that the Catholic religion should be held as the only religion of the State, to the exclusion of all other forms of worship.—Allocution "Nemo vestrum," July 26, 1855.
  78. Hence it has been wisely decided by law, in some Catholic countries, that persons coming to reside therein shall enjoy the public exercise of their own peculiar worship.—Allocution "Acerbissimum," Sept. 27, 1852.
  79. Moreover, it is false that the civil liberty of every form of worship, and the full power, given to all, of overtly and publicly manifesting any opinions whatsoever and thoughts, conduce more easily to corrupt the morals and minds of the people, and to propagate the pest of indifferentism.—Allocution "Nunquam fore," Dec. 15, 1856.
  80. The Roman Pontiff can, and ought to, reconcile himself, and come to terms with progress, liberalism and modern civilization.—Allocution "Jamdudum cernimus," March 18, 1861.

Read also Abp. Lefebvre's Open Letter to Confused Catholics, ch. 11 "Religious Liberty".

[Insanis]

2. This Vatican Council declares that the human person has a right to religious freedom.

If you read it with the idea that true religion is being addressed, and the "right" is the free pursuit of this without coercion, perhaps it is less objectionable.

It starts out with:

...

First, the council professes its belief that God Himself has made known to mankind the way in which men are to serve Him, and thus be saved in Christ and come to blessedness. We believe that this one true religion subsists in the Catholic and Apostolic Church, to which the Lord Jesus committed the duty of spreading it abroad among all men.

And that people need to come to this one true religious without force, but on their own, and this is actually quite true, and it is a good way to avoid infiltrators.

If there is one true religion, then there are many false religions, and it is better for non-believers to be in them, then hiding in the folds of the true believers.

15. Every man is free to embrace and profess that religion which, guided by the light of reason, he shall consider true. ? Allocution ?Maxima quidem,? June 9, 1862; Damnatio ?Multiplices inter,? June 10, 1851.

The idea that false religions are "true" is not within the text of the document being compared. It explicitly states there is one true religion and the freedom to exercise religion is within this context.

2. This Vatican Council declares that the human person has a right to religious freedom. This freedom means that all men are to be immune from coercion on the part of individuals or of social groups and of any human power, in such wise that no one is to be forced to act in a manner contrary to his own beliefs, whether privately or publicly, whether alone or in association with others, within due limits.

To true religion, and perhaps telling the world that the Church wants the right of members of this true religion to be allowed freedom.

The Church never held that it could compel people to truly believe in the true doctrines of the faith.

[Geremia]

If that's what DH intended, why didn't it say "Christian" or "Catholic" instead of "human person"?
This is not true:

2. This Vatican Council declares that the human person has a right to religious freedom. This freedom means that all men [baptized and unbaptized] are to be immune from coercion on the part of individuals or of social groups and of any human power, in such wise that no one is to be forced to act in a manner contrary to his own beliefs, whether privately or publicly, whether alone or in association with others, within due limits.

The Church has the right to coerce the baptized. Trent sess. 7 can. 14:

If anyone says, that those who have been thus baptized when children, are, when they have grown up, to be asked whether they will ratify what their sponsors promised in their names when they were baptized, and that, if they should answer that they will not, they are to be left to their own will, and are not to be compelled meanwhile to a Christian life by any other penalty (nec alia interim poena ad christianam vitam cogendos), save that they be excluded from the participation of the Eucharist, and of the other sacraments, until they repent; let him be anathema.

See Integralism ch. 11 The Two Swords.

[Michael Wilson]

D.H. Is not speaking of the right of men to practice the true religion, but of the right of every man to practice that religion which he thinks is the true religion. The first is true, the next is not.

[Insanis]

D.H. Is not speaking of the right of men to practice the true religion, but of the right of every man to practice that religion which he thinks is the true religion. The first is true, the next is not.

It explicitly states what the one true religion is right in the beginning.

[Michael Wilson]

Insanis,
I just had this very same discussion on this thread: https://www.suscipedomine.com/forum/index.php?topic=25368.0
No use fighting over the same ground twice.