From a8e73a544ca446fe3579f2b300ee398bef59da28 Mon Sep 17 00:00:00 2001
From: Kristian Evers <kristianevers@gmail.com>
Date: Thu, 20 Oct 2016 21:56:06 +0200
Subject: Fixes #138 (spherical tmerc with negative northing gives inverted
 latitude)

---
 src/PJ_tmerc.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/PJ_tmerc.c b/src/PJ_tmerc.c
index 0ae683bf..793f1e95 100644
--- a/src/PJ_tmerc.c
+++ b/src/PJ_tmerc.c
@@ -1,12 +1,12 @@
 #define PJ_LIB__
-#include    <projects.h>
+#include <projects.h>
 
 PROJ_HEAD(tmerc, "Transverse Mercator") "\n\tCyl, Sph&Ell";
 
 
 struct pj_opaque {
-    double  esp; \
-    double  ml0; \
+    double  esp;
+    double  ml0;
     double  *en;
 };
 
@@ -146,7 +146,10 @@ static LP s_inverse (XY xy, PJ *P) {           /* Spheroidal, inverse */
     g = .5 * (h - 1. / h);
     h = cos (P->phi0 + xy.y / P->opaque->esp);
     lp.phi = asin(sqrt((1. - h * h) / (1. + g * g)));
-    if (xy.y < 0.) lp.phi = -lp.phi;
+
+    /* Make sure that phi is on the correct hemisphere when false northing is used */
+    if (xy.y < 0. && -lp.phi+P->phi0 < 0.0) lp.phi = -lp.phi;
+
     lp.lam = (g || h) ? atan2 (g, h) : 0.;
     return lp;
 }
-- 
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