Update SubmittingPatches to add MUA specific notes.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/SubmittingPatches

@@ -128,3 +128,113 @@ then you just add a line saying
 Some people also put extra tags at the end.  They'll just be ignored for
 now, but you can do this to mark internal company procedures or just
 point out some special detail about the sign-off.
+
+
+------------------------------------------------
+MUA specific hints
+
+Some of patches I receive or pick up from the list share common
+patterns of breakage.  Please make sure your MUA is set up
+properly not to corrupt whitespaces.  Here are two common ones
+I have seen:
+
+* Empty context lines that do not have _any_ whitespace.
+
+* Non empty context lines that have one extra whitespace at the
+  beginning.
+
+
+Pine
+----
+
+(Johannes Schindelin)
+
+I don't know how many people still use pine, but for those poor
+souls it may be good to mention that the quell-flowed-text is
+needed for recent versions.
+
+... the "no-strip-whitespace-before-send" option, too. AFAIK it
+was introduced in 4.60.
+
+(Linus Torvalds)
+
+And 4.58 needs at least this.
+
+---
+diff-tree 8326dd8350be64ac7fc805f6563a1d61ad10d32c (from e886a61f76edf5410573e92e38ce22974f9c40f1)
+Author: Linus Torvalds <torvalds@g5.osdl.org>
+Date:   Mon Aug 15 17:23:51 2005 -0700
+
+    Fix pine whitespace-corruption bug
+
+    There's no excuse for unconditionally removing whitespace from
+    the pico buffers on close.
+
+diff --git a/pico/pico.c b/pico/pico.c
+--- a/pico/pico.c
++++ b/pico/pico.c
+@@ -219,7 +219,9 @@ PICO *pm;
+ 	    switch(pico_all_done){	/* prepare for/handle final events */
+ 	      case COMP_EXIT :		/* already confirmed */
+ 		packheader();
++#if 0
+ 		stripwhitespace();
++#endif
+ 		c |= COMP_EXIT;
+ 		break;
+ 
+
+
+Thunderbird
+-----------
+
+(A Large Angry SCM)
+
+Here are some hints on how to successfully submit patches inline using
+Thunderbird.
+
+This recipe appears to work with the current [*1*] Thunderbird from Suse.
+
+The following Thunderbird extensions are needed:
+	AboutConfig 0.5
+		http://aboutconfig.mozdev.org/
+	External Editor 0.5.4
+		http://extensionroom.mozdev.org/more-info/exteditor
+
+1) Prepare the patch as a text file using your method of choice.
+
+2) Before opening a compose window, use Edit->Account Settings to
+uncheck the "Compose messages in HTML format" setting in the
+"Composition & Addressing" panel of the account to be used to send the
+patch. [*2*]
+
+3) In the main Thunderbird window, _before_ you open the compose window
+for the patch, use Tools->about:config to set the following to the
+indicated values:
+	mailnews.send_plaintext_flowed	=> false
+	mailnews.wraplength		=> 999
+
+4) Open a compose window and click the external editor icon.
+
+5) In the external editor window, read in the patch file and exit the
+editor normally.
+
+6) Back in the compose window: Add whatever other text you wish to the
+message, complete the addressing and subject fields, and press send.
+
+7) Optionally, undo the about:config/account settings changes made in
+steps 2 & 3.
+
+
+[Footnotes]
+*1* Version 1.0 (20041207) from the MozillaThunderbird-1.0-5 rpm of Suse
+9.3 professional updates.
+
+*2* It may be possible to do this with about:config and the following
+settings but I haven't tried, yet.
+	mail.html_compose			=> false
+	mail.identity.default.compose_html	=> false
+	mail.identity.id?.compose_html		=> false
+
+
+