fixing trace(coerce, ..) etc

git-svn-id: https://svn.r-project.org/R/trunk@87971 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: maechler

doc/NEWS.Rd

@@ -751,6 +751,9 @@
       as \code{NA}.
 
       \item \code{vignette("reshape")} is now also available on Windows.
+
+      \item \code{trace(coerce, ..)} now works correctly, fixing \PR{18823}
+      thanks to \I{Mikael Jagan}.
     }
   }
 }

src/library/methods/R/as.R

@@ -1,7 +1,7 @@
 #  File src/library/methods/R/as.R
 #  Part of the R package, https://www.R-project.org
 #
-#  Copyright (C) 1995-2019 The R Core Team
+#  Copyright (C) 1995-2025 The R Core Team
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -91,6 +91,9 @@ as <-
 	    }
         }
     }
+    environment(asMethod) <- asMethodEnv <- new.env(parent = environment(asMethod))
+    loadMethod(asMethod, envir = asMethodEnv)
+    assign(".Generic", asMethod@generic, envir = asMethodEnv)
     if(strict)
         asMethod(object)
     else

tests/classes-methods.R

@@ -193,5 +193,21 @@ if(hasME) {
 }
 
 
+## trace(), debug() etc for  coerce methods -- PR#18823
+trr <- quote(list(.Generic, .Method, .defined, .target))
+sig <- c("ANY", "logical")
+m0 <- selectMethod(coerce, signature = sig)
+a0 <- as(0, "logical") # just `FALSE`
+trace(coerce, tracer = trr, signature = sig)
+m1 <- selectMethod(coerce, signature = sig)
+a1 <- as(0, "logical") # error  "object '.Generic' not found"  in R <= 4.4.3
+untrace(coerce, signature = sig)
+m2 <- selectMethod(coerce, signature = sig)
+stopifnot( is(m0, "MethodDefinition"),
+          !is(m0, "MethodDefinitionWithTrace"),
+           is(m1, "MethodDefinitionWithTrace"),
+          identical(m0, m2), identical(a0, a1))
+
+
 
 cat('Time elapsed: ', proc.time(),'\n')