docs: document zsh specialty with empty here-documents.

* doc/autoconf.texi (Here-Documents): zsh 4.3.10 adds a newline
to empty here-docs.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

diff --git a/ChangeLog b/ChangeLog
index 2c83e2b9ec644a4fae97ac431c7ab5fed2e3ef11..9431c94d758fa10eafe81e2b90e922305cfd0eb6 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-09-13  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
+           Gary V. Vaughan <gary@gnu.org>
+
+       docs: document zsh specialty with empty here-documents.
+       * doc/autoconf.texi (Here-Documents): zsh 4.3.10 adds a newline
+       to empty here-docs.
+
 2010-09-13  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
        docs: document zsh special array $options.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index f11f1dd82f386a0ca0b1a185a0a5dd6d186dc9c2..71eefa40d6f48fbccda02aa1ce14f9f885ac1939 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -14897,6 +14897,15 @@ fixed in
 @samp{ksh93g} (1998-04-30) but as of 2006 many operating systems were
 still shipping older versions with the bug.
 
+Empty here-documents are not portable either; with the following code,
+@command{zsh} up to at least version 4.3.10 creates a file with a single
+newline, whereas other shells create an empty file:
+
+@example
+cat >file <<EOF
+EOF
+@end example
+
 Many shells (including the Bourne shell) implement here-documents
 inefficiently.  In particular, some shells can be extremely inefficient when
 a single statement contains many here-documents.  For instance if your