21296: Add ERR alias for ZERR where possible.

"trap" reports alias names.

2 files changed, 7 insertions, 2 deletions

diff --git a/Doc/Zsh/builtins.yo b/Doc/Zsh/builtins.yo
index a5b6ea620..6eb94cbfb 100644
--- a/Doc/Zsh/builtins.yo
+++ b/Doc/Zsh/builtins.yo
@@ -1165,7 +1165,9 @@ default values.  If var(arg) is the empty string, then this signal
 is ignored by the shell and by the commands it invokes.
 
 If var(sig) is tt(ZERR) then var(arg) will be executed
-after each command with a nonzero exit status.
+after each command with a nonzero exit status.  tt(ERR) is an alias
+for tt(ZERR) on systems that have no tt(SIGERR) signal (this is the
+usual case).
 If var(sig) is tt(DEBUG) then var(arg) will be executed
 after each command.
 If var(sig) is tt(0) or tt(EXIT)
diff --git a/Doc/Zsh/func.yo b/Doc/Zsh/func.yo
index bf5a9b2ae..2f6445873 100644
--- a/Doc/Zsh/func.yo
+++ b/Doc/Zsh/func.yo
@@ -222,11 +222,14 @@ Executed when the shell exits,
 or when the current function exits if defined inside a function.
 )
 findex(TRAPZERR)
+findex(TRAPERR)
 item(tt(TRAPZERR))(
 Executed whenever a command has a non-zero exit status.  However, the
 function is not executed if the command occurred in a sublist followed by
 `tt(&&)' or `tt(||)'; only the final command in a sublist of this type
-causes the trap to be executed.
+causes the trap to be executed.  The function tt(TRAPERR) acts the same as
+tt(TRAPZERR) on systems where there is no tt(SIGERR) (this is the usual
+case).
 )
 enditem()