Gitweb:
http://git.exim.org/exim.git/commitdiff/6286d7c431cce300d03403b63e16ba34fab41f1e
Commit: 6286d7c431cce300d03403b63e16ba34fab41f1e
Parent: 14a465c3f0ae93b383f57f12b2ac8709ac0d55b6
Author: Todd Lyons <tlyons@???>
AuthorDate: Thu Aug 28 17:09:03 2014 -0700
Committer: Todd Lyons <tlyons@???>
CommitDate: Thu Aug 28 17:09:03 2014 -0700
Bugzilla 1518: Clarify router "condition" parsing
---
doc/doc-docbook/spec.xfpt | 33 +++++++++++++++++++++++++++++++++
doc/doc-txt/ChangeLog | 5 +++++
2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 837af5a..4d620a3 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -16822,6 +16822,39 @@ If the expansion fails (other than forced failure) delivery is deferred. Some
of the other precondition options are common special cases that could in fact
be specified using &%condition%&.
+.new
+When originally designed, Exim's ACL system enforced very strict parsing
+of the &%condition%& expansion everywhere it was being processed.
+Through the 4.7x release cycle, the &%condition%& processing while in a
+router became more loose, internally adopting the use of &%bool_lax%&
+instead of the more rigid &%bool%&. This is best illustrated in an
+example:
+.code
+# This used to fail with a syntax error, now it
+# treats any extra characters as a string
+
+$ exim -be '${if eq {${lc:GOOGLE.com}} {google.com}} {yes} {no}}'
+true {yes} {no}}
+
+$ exim -be '${if eq {${lc:WHOIS.com}} {google.com}} {yes} {no}}'
+ {yes} {no}}
+.endd
+In each example above, the &%if%& statement actually ends after
+&"{google.com}}"&. Since no true or false braces were defined, the
+default &%if%& behavior is to return a boolean true or a null answer
+(which evaluates to false). The rest of the line is then treated as a
+string. So the first example resulted in the boolean answer &"true"&
+with the string &" {yes} {no}}"& appended to it. The second example
+resulted in the null output (indicating false) with the string
+&" {yes} {no}}"& appended to it.
+
+In fact you can put excess forward braces in too. In the router
+&%condition%&, Exim's ACL parser only looks for &"{"& symbols when they
+mean something, like after a &"$"& or when required as part of a
+conditional. But otherwise &"{"& and &"}"& are treated as ordinary
+string characters.
+.wen
+
.option debug_print routers string&!! unset
.cindex "testing" "variables in drivers"
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index cb35141..2caf9ed 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -20,6 +20,11 @@ TL/02 The BSD's have an arc4random API. One of the functions to induce
JH/01 Expand the EXPERIMENTAL_TPDA feature. Several different events now
cause callback expansion.
+TL/03 Bugzilla 1518: Clarify "condition" processing in routers; that
+ syntax errors in an expansion can be treated as a string instead of
+ logging or causing an error, due to the internal use of bool_lax
+ instead of bool when processing it.
+
Exim version 4.84
-----------------
