Avoid upos underflowing in match loop

(cherry picked from commit 09462bda7f8da4e59307e0d6a7446d499c1da34c)

diff --git a/ext/yahttp/yahttp/router.cpp b/ext/yahttp/yahttp/router.cpp
index fdf23a45c516d861b1d9358ec02f49ab4819b08d..5f6885a887b444dc0b3ad720a292350966663719 100644 (file)
--- a/ext/yahttp/yahttp/router.cpp
+++ b/ext/yahttp/yahttp/router.cpp
@@ -62,8 +62,15 @@ namespace YaHTTP {
           }
           nend = upos;
           params[pname] = funcptr::tie(nstart, nend);
-
-          upos--;
+          if (upos > 0) {
+            upos--;
+          }
+          else {
+            // If upos is zero, do not decrement it and then increment at bottom of loop, this disturbs Coverity.
+            // Only increment rpos and continue loop
+            rpos++;
+            continue;
+          }
         }
         else if (route[rpos] != requrl.path[upos]) {
           break;