diff options
Diffstat (limited to 'src/projections/imw_p.cpp')
| -rw-r--r-- | src/projections/imw_p.cpp | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/projections/imw_p.cpp b/src/projections/imw_p.cpp index 723fcc48..41882df2 100644 --- a/src/projections/imw_p.cpp +++ b/src/projections/imw_p.cpp @@ -116,7 +116,12 @@ static PJ_LP e_inverse (PJ_XY xy, PJ *P) { /* Ellipsoidal, inverse */ lp.lam = xy.x / cos(lp.phi); do { t = loc_for(lp, P, &yc); - lp.phi = ((lp.phi - Q->phi_1) * (xy.y - yc) / (t.y - yc)) + Q->phi_1; + const double denom = t.y - yc; + if( denom == 0 ) { + proj_errno_set(P, PJD_ERR_NON_CONVERGENT); + return proj_coord_error().lp; + } + lp.phi = ((lp.phi - Q->phi_1) * (xy.y - yc) / denom) + Q->phi_1; lp.lam = lp.lam * xy.x / t.x; i ++; } while (i < N_MAX_ITER && @@ -124,7 +129,8 @@ static PJ_LP e_inverse (PJ_XY xy, PJ *P) { /* Ellipsoidal, inverse */ if( i == N_MAX_ITER ) { - lp.lam = lp.phi = HUGE_VAL; + proj_errno_set(P, PJD_ERR_NON_CONVERGENT); + return proj_coord_error().lp; } return lp; |