From ed2b26a09b407f7b580297d8a2cc516f786cbcc6 Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Fri, 15 Mar 2019 22:24:31 +0100
Subject: Hammer: avoid division by zero

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12799
Credit to OSS Fuzz
---
 src/projections/hammer.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'src/projections')

diff --git a/src/projections/hammer.cpp b/src/projections/hammer.cpp
index aa7d1ba9..b2e56a2c 100644
--- a/src/projections/hammer.cpp
+++ b/src/projections/hammer.cpp
@@ -24,7 +24,14 @@ static PJ_XY s_forward (PJ_LP lp, PJ *P) {           /* Spheroidal, forward */
     struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
     double cosphi, d;
 
-    d = sqrt(2./(1. + (cosphi = cos(lp.phi)) * cos(lp.lam *= Q->w)));
+    cosphi = cos(lp.phi);
+    lp.lam *= Q->w;
+    double denom = 1. + cosphi * cos(lp.lam);
+    if( denom == 0.0 ) {
+        proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+        return proj_coord_error().xy;
+    }
+    d = sqrt(2./denom);
     xy.x = Q->m * d * cosphi * sin(lp.lam);
     xy.y = Q->rm * d * sin(lp.phi);
     return xy;
-- 
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