[PATCH] 'functions -T' tracing: recurse into anonymous functions.

[Daniel Shahaf <d.s@daniel.shahaf.name>]

---
 Doc/Zsh/builtins.yo |  2 +-
 Src/exec.c          | 12 +++++++++---
 Test/E02xtrace.ztst | 17 +++++++++++++++++
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/Doc/Zsh/builtins.yo b/Doc/Zsh/builtins.yo
index 1ca1f24..813b725 100644
--- a/Doc/Zsh/builtins.yo
+++ b/Doc/Zsh/builtins.yo
@@ -2029,7 +2029,7 @@ can be made, and the only other valid flags are tt(-t), tt(-T), tt(-k),
 tt(-u), tt(-U) and tt(-z).  The flag tt(-t) turns on execution tracing
 for this function; the flag tt(-T) does the same, but turns off tracing
 on any function called from the present one, unless that function also
-has the tt(-t) or tt(-T) flag.  The tt(-u) and tt(-U) flags cause the
+has the tt(-t) or tt(-T) flag or is anonymous.  The tt(-u) and tt(-U) flags cause the
 function to be marked for autoloading; tt(-U) also causes alias
 expansion to be suppressed when the function is loaded.  See the
 description of the `tt(autoload)' builtin for details.
diff --git a/Src/exec.c b/Src/exec.c
index 2dcd5bc..515406f 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -4615,6 +4615,8 @@ exectime(Estate state, UNUSED(int do_exec))
 
 /* Define a shell function */
 
+static const char *const ANONYMOUS_FUNCTION_NAME = "(anon)";
+
 /**/
 static int
 execfuncdef(Estate state, Eprog redir_prog)
@@ -4732,7 +4734,7 @@ execfuncdef(Estate state, Eprog redir_prog)
 
 	    if (!args)
 		args = newlinklist();
-	    shf->node.nam = "(anon)";
+	    shf->node.nam = (char *) ANONYMOUS_FUNCTION_NAME;
 	    pushnode(args, shf->node.nam);
 
 	    execshfunc(shf, args);
@@ -5165,8 +5167,12 @@ doshfunc(Shfunc shfunc, LinkList doshargs, int noreturnval)
 
 	if (flags & (PM_TAGGED|PM_TAGGED_LOCAL))
 	    opts[XTRACE] = 1;
-	else if (oflags & PM_TAGGED_LOCAL)
-	    opts[XTRACE] = 0;
+	else if (oflags & PM_TAGGED_LOCAL) {
+	    if (shfunc->node.nam == ANONYMOUS_FUNCTION_NAME /* pointer comparison */)
+		flags |= PM_TAGGED_LOCAL;
+	    else
+		opts[XTRACE] = 0;
+	}
 	ooflags = oflags;
 	/*
 	 * oflags is static, because we compare it on the next recursive
diff --git a/Test/E02xtrace.ztst b/Test/E02xtrace.ztst
index 093a587..6e425e7 100644
--- a/Test/E02xtrace.ztst
+++ b/Test/E02xtrace.ztst
@@ -127,3 +127,20 @@
 ?+(eval):2> [[ 'f o' == f\ x* || 'b r' != z\ o && 'squashy sound' < 'squishy sound' ]]
 ?+(eval):3> [[ -e nonexistentfile || -z '' && -t 3 ]]
 ?+(eval):4> set +x
+
+  # Part 1: Recurses into nested anonymous functions
+  fn() {
+    () { () { true } }
+  }
+  functions -T fn
+  fn
+  # Part 2: Doesn't recurse into named functions
+  gn() { true }
+  fn() { gn }
+  functions -T fn
+  fn
+0:tracing recurses into anonymous functions
+?+fn:1> '(anon)'
+?+(anon):0> '(anon)'
+?+(anon):0> true
+?+fn:0> gn