devel/readline: fix build failure on DragonFly

[dragonflybot]

Generated by the DragonFly agentic build-fix loop and verified in a clean dev-env. Reviewed and accepted by operator operator before submission.

Problem

The build failed on @2026Q2 — classified compile-error, confidence medium.

The FreeBSD base port applies a patch to terminal.c that adds the cons25 termtype to the dumbterm assignment. During materialisation into DeltaPorts the patch was not applied correctly – the leading + from the patch’s unified-diff context ended up as a literal character in the source line. This turns the expression into + dumbterm, a unary-plus that is not an lvalue, and the compiler rejects it.

Evidence:

• Compile error and the offending line (with a literal leading +):

  ./terminal.c: In function '_rl_init_terminal_io':
  ./terminal.c:583:13: error: lvalue required as left operand of assignment
   +  dumbterm = STREQ (term, "dumb") || STREQ (term, "vt52") || STREQ (term, "adm3a") || STREQ (term, "cons25");
             ^
  

• cons25 is a FreeBSD-specific console terminal type; it does not exist in upstream GNU readline source. This confirms that a FreeBSD-originated patch modified terminal.c, and that the patch was mangled when applied.

Fix

Automated fix for the build failure in devel/readline.

What changed

1 file changed, +1/-0

• ports/devel/readline/overlay.dops

Verification

Built successfully in a DragonFly dev-env (dsynth) for target @2026Q2.
Verified 2026-05-28T22:56:55.782297+00:00.

Provenance

• Operator: operator
• Agent: model=deepseek/deepseek-v4-pro attempts=1 tokens=147077