From: Simon Schubert <2@0x2c.org>
Date: Wed, 7 Dec 2011 11:39:46 +0000 (+0100)
Subject: deliver_local: quote "From " more liberally
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=fedbe7114e3ea26e2a46f4e001879d429018c1f0;p=people%2Fms%2Fdma.git

deliver_local: quote "From " more liberally

It seems that when scanning for mails in mbox files, most MUAs just
look for lines beginning with "From ", and not only for "From " lines
after an empty line.  Therefore quote "From " more liberally, and also
implement the mboxro format by quoting />*From / lines that have been
quoted before.

Reported-by: Pierre Frenkiel <pierre.frenkiel@gmail.com>
---

diff --git a/dma.h b/dma.h
index a1e4b8c..64ad9e6 100644
--- a/dma.h
+++ b/dma.h
@@ -77,6 +77,10 @@
 #define DMA_ROOT_USER	"mail"
 #define DMA_GROUP	"mail"
 
+#ifndef MBOX_STRICT
+#define MBOX_STRICT	0
+#endif
+
 
 struct stritem {
 	SLIST_ENTRY(stritem) next;
diff --git a/local.c b/local.c
index 694dd84..6a6407e 100644
--- a/local.c
+++ b/local.c
@@ -214,7 +214,17 @@ retry:
 			goto chop;
 		}
 
-		if (hadnl && strncmp(line, "From ", 5) == 0) {
+		/*
+		 * mboxro processing:
+		 * - escape lines that start with "From " with a > sign.
+		 * - be reversable by escaping lines that contain an arbitrary
+		 *   number of > signs, followed by "From ", i.e. />*From / in regexp.
+		 * - strict mbox processing only requires escaping after empty lines,
+		 *   yet most MUAs seem to relax this requirement and will treat any
+		 *   line starting with "From " as the beginning of a new mail.
+		 */
+		if ((!MBOX_STRICT || hadnl) &&
+		    strncmp(&line[strspn(line, ">")], "From ", 5) == 0) {
 			const char *gt = ">";
 
 			if (write(mbox, gt, 1) != 1)
diff --git a/test/quote.rfc2822 b/test/quote.rfc2822
new file mode 100644
index 0000000..f0f52fd
--- /dev/null
+++ b/test/quote.rfc2822
@@ -0,0 +1,23 @@
+From: test <test@example.org>
+To: test <test@example.org>
+Subject: testing!
+
+From what i can see...
+
+He came along,
+from far away.
+
+The rabbit comes out
+From his rabbit hole.
+
+Fromtal nudity!
+
+> From the previous mail
+
+>From the quote
+
+From here
+From there
+>>>From everywhere.
+
+last line.