Switch utm to use etmerc to address issue #316.

Add a test to check this.  Output of an existing test changed in 7th
decimal place.

5 files changed, 61 insertions, 31 deletions

diff --git a/nad/testvarious b/nad/testvarious
index c213456e..0ea4c133 100755
--- a/nad/testvarious
+++ b/nad/testvarious
@@ -675,19 +675,36 @@ echo "##############################################################" >> ${OUT}
 echo "Test bug 245 (use +datum=carthage)" >> ${OUT}
 #
 $EXE -f '%.7f' \
-     +proj=longlat +datum=WGS84 +nodefs +to +proj=utm +zone=32 +datum=carthage +nodefs \
+     +proj=longlat +datum=WGS84 +no_defs +to +proj=utm +zone=32 +datum=carthage +no_defs \
  -E >>${OUT} <<EOF
 10 34
 EOF
 echo "##############################################################" >> ${OUT}
-echo "Test bug 245 (use expension of +datum=carthage)" >> ${OUT}
+echo "Test bug 245 (use expansion of +datum=carthage)" >> ${OUT}
 #
 $EXE -f '%.7f' \
-     +proj=longlat +datum=WGS84 +nodefs +to +proj=utm +zone=32 +a=6378249.2 +b=6356515 +towgs84=-263.0,6.0,431.0 +nodefs \
+     +proj=longlat +datum=WGS84 +no_defs +to +proj=utm +zone=32 +a=6378249.2 +b=6356515 +towgs84=-263.0,6.0,431.0 +no_defs \
  -E >>${OUT} <<EOF
 10 34
 EOF
 ##############################################################################
+echo "##############################################################" >> ${OUT}
+echo "Test issue #316 (switch utm to use etmerc)" >> ${OUT}
+#
+$EXE -f '%.6f' \
+     +proj=latlong +datum=WGS84 +no_defs +to +proj=utm +zone=35 +datum=WGS84 +no_defs \
+ -E >>${OUT} <<EOF
+0 83
+EOF
+##############################################################################
+echo "##############################################################" >> ${OUT}
+echo "Test issue #316 (switch utm to use etmerc)" >> ${OUT}
+#
+$EXE -f '%.6f' \
+     +proj=latlong +datum=WGS84 +no_defs +to +proj=etmerc +datum=WGS84 +no_defs +k=0.9996 +lon_0=27 +x_0=500000 -f %.6f \
+ -E >>${OUT} <<EOF
+0 83
+EOF
 # Done!
 # do 'diff' with distribution results
 echo "diff ${OUT} with ${OUT}.dist"
diff --git a/nad/tv_out.dist b/nad/tv_out.dist
index 76d5b1e2..00063c47 100644
--- a/nad/tv_out.dist
+++ b/nad/tv_out.dist
@@ -313,7 +313,13 @@ Test bug 244 (2)
 987122.418330284 -14429896.539530909	-140.10000000000	-87.00000000000 0.00000000000
 ##############################################################
 Test bug 245 (use +datum=carthage)
-10 34	592302.9819462	3762148.7340610 -30.3110170
+10 34	592302.9819461	3762148.7340609 -30.3110170
 ##############################################################
-Test bug 245 (use expension of +datum=carthage)
-10 34	592302.9819462	3762148.7340610 -30.3110170
+Test bug 245 (use expansion of +datum=carthage)
+10 34	592302.9819461	3762148.7340609 -30.3110170
+##############################################################
+Test issue #316 (switch utm to use etmerc)
+0 83	145723.870553	9300924.845226 0.000000
+##############################################################
+Test issue #316 (switch utm to use etmerc)
+0 83	145723.870553	9300924.845226 0.000000
diff --git a/src/PJ_tmerc.c b/src/PJ_tmerc.c
index 3b1e0fb5..70e8e72f 100644
--- a/src/PJ_tmerc.c
+++ b/src/PJ_tmerc.c
@@ -5,8 +5,6 @@
 #define PJ_LIB__
 #include	<projects.h>
 PROJ_HEAD(tmerc, "Transverse Mercator") "\n\tCyl, Sph&Ell";
-PROJ_HEAD(utm, "Universal Transverse Mercator (UTM)")
-	"\n\tCyl, Sph\n\tzone= south";
 #define EPS10	1.e-10
 #define aks0	P->esp
 #define aks5	P->ml0
@@ -153,23 +151,3 @@ setup(PJ *P) { /* general initialization */
 }
 ENTRY1(tmerc, en)
 ENDENTRY(setup(P))
-ENTRY1(utm, en)
-	int zone;
-
-	if (!P->es) E_ERROR(-34);
-	P->y0 = pj_param(P->ctx, P->params, "bsouth").i ? 10000000. : 0.;
-	P->x0 = 500000.;
-	if (pj_param(P->ctx, P->params, "tzone").i) /* zone input ? */
-		if ((zone = pj_param(P->ctx, P->params, "izone").i) > 0 && zone <= 60)
-			--zone;
-		else
-			E_ERROR(-35)
-	else /* nearest central meridian input */
-		if ((zone = floor((adjlon(P->lam0) + PI) * 30. / PI)) < 0)
-			zone = 0;
-		else if (zone >= 60)
-			zone = 59;
-	P->lam0 = (zone + .5) * PI / 30. - PI;
-	P->k0 = 0.9996;
-	P->phi0 = 0.;
-ENDENTRY(setup(P))
diff --git a/src/proj_etmerc.c b/src/proj_etmerc.c
index 1097eb3c..a5351f5d 100644
--- a/src/proj_etmerc.c
+++ b/src/proj_etmerc.c
@@ -52,6 +52,8 @@
 
 PROJ_HEAD(etmerc, "Extended Transverse Mercator")
     "\n\tCyl, Sph\n\tlat_ts=(0)\nlat_0=(0)";
+PROJ_HEAD(utm, "Universal Transverse Mercator (UTM)")
+	"\n\tCyl, Sph\n\tzone= south";
 
 #define PROJ_ETMERC_ORDER 6
 
@@ -211,7 +213,8 @@ INVERSE(e_inverse); /* ellipsoid */
 
 FREEUP; if (P) free(P); }
 
-ENTRY0(etmerc)
+	static PJ *
+setup(PJ *P) { /* general initialization */
     double f, n, np, Z;
 
     if (P->es <= 0) E_ERROR(-34);
@@ -286,4 +289,30 @@ ENTRY0(etmerc)
     P->Zb  = - P->Qn*(Z + clens(P->gtu, PROJ_ETMERC_ORDER, 2*Z));
     P->inv = e_inverse;
     P->fwd = e_forward;
-ENDENTRY(P)
+	return P;
+}
+
+ENTRY0(etmerc)
+ENDENTRY(setup(P))
+
+/* utm uses etmerc for the underlying projection */
+ENTRY0(utm)
+	int zone;
+
+	if (!P->es) E_ERROR(-34);
+	P->y0 = pj_param(P->ctx, P->params, "bsouth").i ? 10000000. : 0.;
+	P->x0 = 500000.;
+	if (pj_param(P->ctx, P->params, "tzone").i) /* zone input ? */
+		if ((zone = pj_param(P->ctx, P->params, "izone").i) > 0 && zone <= 60)
+			--zone;
+		else
+			E_ERROR(-35)
+	else /* nearest central meridian input */
+		if ((zone = floor((adjlon(P->lam0) + PI) * 30. / PI)) < 0)
+			zone = 0;
+		else if (zone >= 60)
+			zone = 59;
+	P->lam0 = (zone + .5) * PI / 30. - PI;
+	P->k0 = 0.9996;
+	P->phi0 = 0.;
+ENDENTRY(setup(P))
diff --git a/src/projects.h b/src/projects.h
index fe6a44c6..43287849 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -316,7 +316,7 @@ extern struct PJ_PRIME_MERIDIANS pj_prime_meridians[];
 #endif
 
 #ifdef PJ_LIB__
-    /* repeatative projection code */
+    /* repetitive projection code */
 #define PROJ_HEAD(id, name) static const char des_##id [] = name
 #define ENTRYA(name) \
         C_NAMESPACE_VAR const char * const pj_s_##name = des_##name; \