commit f71dee6: [Fix] Fix quoted-printable soft newlines bugged case

[Vsevolod Stakhov]

Author: Vsevolod Stakhov
Date: 2020-11-20 15:55:39 +0000
URL: https://github.com/rspamd/rspamd/commit/f71dee6d40be52c69f5a90536e811db8e1f852f1 (HEAD -> master)

[Fix] Fix quoted-printable soft newlines bugged case

---
 src/libutil/str_util.c             | 12 ++++++++----
 test/lua/unit/quoted_printable.lua | 10 ++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/libutil/str_util.c b/src/libutil/str_util.c
index 1e7d0b06b..2e1fd6a0d 100644
--- a/src/libutil/str_util.c
+++ b/src/libutil/str_util.c
@@ -2341,15 +2341,19 @@ decode:
 			if      (c >= '0' && c <= '9') { ret = c - '0'; }
 			else if (c >= 'A' && c <= 'F') { ret = c - 'A' + 10; }
 			else if (c >= 'a' && c <= 'f') { ret = c - 'a' + 10; }
-			else if (c == '\r' || c == '\n') {
-				/* Soft line break */
-				while (remain > 0 && (*p == '\r' || *p == '\n')) {
-					remain --;
+			else if (c == '\r') {
+				/* Eat one more endline */
+				if (remain > 0 && *p == '\n') {
 					p ++;
+					remain --;
 				}
 
 				continue;
 			}
+			else if (c == '\n') {
+				/* Soft line break */
+				continue;
+			}
 			else {
 				/* Hack, hack, hack, treat =<garbadge> as =<garbadge> */
 				if (remain > 0) {
diff --git a/test/lua/unit/quoted_printable.lua b/test/lua/unit/quoted_printable.lua
index cf667f8d4..29df0254d 100644
--- a/test/lua/unit/quoted_printable.lua
+++ b/test/lua/unit/quoted_printable.lua
@@ -102,6 +102,16 @@ context("Quoted-Printable encoding", function()
       'Mailscape External Mail Flow Outbound Test=',
       'asan found'
     },
+    {
+      'foo=\n\nbar',
+      'foo\nbar',
+      'Soft newline followed by hard newline (LF)',
+    },
+    {
+      'foo=\r\n\r\nbar',
+      'foo\r\nbar',
+      'Soft newline followed by hard newline (CRLF)',
+    },
   }
 
   for _,c in ipairs(cases) do