Add capability to read resource files from the user writable directory

7 files changed, 99 insertions, 61 deletions

diff --git a/test/cli/Makefile.am b/test/cli/Makefile.am
index 758352c6..253b85d8 100644
--- a/test/cli/Makefile.am
+++ b/test/cli/Makefile.am
@@ -27,7 +27,7 @@ EXTRA_DIST = pj_out27.dist pj_out83.dist td_out.dist \
 		CMakeLists.txt
 
 testprojinfo-check:
-	PROJ_LIB=$(PROJ_LIB) $(TESTPROJINFO) $(PROJINFOEXE)
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTPROJINFO) $(PROJINFOEXE)
 
 test27-check:
 	$(TEST27) $(PROJEXE)
@@ -36,24 +36,24 @@ test83-check:
 	$(TEST83) $(PROJEXE)
 
 testvarious-check:
-	PROJ_LIB=$(PROJ_LIB) $(TESTVARIOUS) $(CS2CSEXE)
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTVARIOUS) $(CS2CSEXE)
 
 testdatumfile-check:
 	@if [ -f $(PROJ_LIB)/conus -a -f $(PROJ_LIB)/ntv1_can.dat -a -f $(PROJ_LIB)/MD -a -f $(PROJ_LIB)/ntf_r93.gsb -a -f $(PROJ_LIB)/egm96_15.gtx ]; then \
-	  PROJ_LIB=$(PROJ_LIB) $(TESTDATUMFILE) $(CS2CSEXE) ; \
+	  PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTDATUMFILE) $(CS2CSEXE) ; \
 	fi
 
 testign-check:
 	@if [ -f $(PROJ_LIB)/ntf_r93.gsb ] ; then \
-	  PROJ_LIB=$(PROJ_LIB) $(TESTIGN) $(CS2CSEXE) ; \
+	  PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTIGN) $(CS2CSEXE) ; \
 	fi
 
 testntv2-check:
 	@if [ -f $(PROJ_LIB)/ntv2_0.gsb -a -f $(PROJ_LIB)/conus -a -f $(PROJ_LIB)/ntv1_can.dat ] ; then \
-	  PROJ_LIB=$(PROJ_LIB) $(TESTNTV2) $(CS2CSEXE) ; \
+	  PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTNTV2) $(CS2CSEXE) ; \
 	fi
 
 testcct-check:
-	PROJ_LIB=$(PROJ_LIB) $(TESTCCT) $(CCTEXE)
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(TESTCCT) $(CCTEXE)
 
 check-local: testprojinfo-check test27-check test83-check testvarious-check testdatumfile-check testign-check testntv2-check testcct-check
diff --git a/test/gie/Makefile.am b/test/gie/Makefile.am
index ff333a14..1539cb2e 100644
--- a/test/gie/Makefile.am
+++ b/test/gie/Makefile.am
@@ -15,33 +15,33 @@ EXTRA_DIST = 4D-API_cs2cs-style.gie \
 PROJ_LIB ?= ../../data
 
 4D-API-cs2cs-style: 4D-API_cs2cs-style.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 GDA: GDA.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 axisswap: axisswap.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 builtins: builtins.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 deformation: deformation.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 ellipsoid: ellipsoid.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 more_builtins: more_builtins.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 unitconvert: unitconvert.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 DHDN_ETRS89: DHDN_ETRS89.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 geotiff_grids: geotiff_grids.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 check-local: 4D-API-cs2cs-style GDA axisswap builtins deformation ellipsoid more_builtins unitconvert DHDN_ETRS89 geotiff_grids
diff --git a/test/gigs/Makefile.am b/test/gigs/Makefile.am
index bea3be59..56493550 100644
--- a/test/gigs/Makefile.am
+++ b/test/gigs/Makefile.am
@@ -23,54 +23,54 @@ EXTRA_DIST = \
 PROJ_LIB ?= ../../data
 
 5101.1: 5101.1-jhs.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5101.2: 5101.2-jhs.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5101.3: 5101.3-jhs.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5101.4: 5101.4-jhs-etmerc.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5102.1: 5102.1.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5103.1: 5103.1.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5103.2: 5103.2.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5103.3: 5103.3.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5105.2: 5105.2.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5106: 5106.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5107: 5107.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5109: 5109.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5111.1: 5111.1.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5112: 5112.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5113: 5113.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5201: 5201.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 5208: 5208.gie
-	PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) $(GIEEXE) $<
 
 check-local: 5101.1 5101.2 5101.3 5101.4 5102.1 5103.1 5103.2 5103.3 5105.2 5106 5107 5109 5111.1 5112 5113 5201 5208
diff --git a/test/unit/CMakeLists.txt b/test/unit/CMakeLists.txt
index 35a6e4c1..e1eefcf0 100644
--- a/test/unit/CMakeLists.txt
+++ b/test/unit/CMakeLists.txt
@@ -71,7 +71,7 @@ target_link_libraries(proj_pj_transform_test
   ${PROJ_LIBRARIES})
 add_test(NAME proj_pj_transform_test COMMAND proj_pj_transform_test)
 set_property(TEST proj_pj_transform_test
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 
 
 add_executable(proj_errno_string_test
@@ -82,7 +82,7 @@ target_link_libraries(proj_errno_string_test
   ${PROJ_LIBRARIES})
 add_test(NAME proj_errno_string_test COMMAND proj_errno_string_test)
 set_property(TEST proj_errno_string_test
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 
 add_executable(proj_angular_io_test
   main.cpp
@@ -92,7 +92,7 @@ target_link_libraries(proj_angular_io_test
   ${PROJ_LIBRARIES})
 add_test(NAME proj_angular_io_test COMMAND proj_angular_io_test)
 set_property(TEST proj_angular_io_test
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 
 add_executable(proj_context_test
   main.cpp
@@ -102,7 +102,7 @@ target_link_libraries(proj_context_test
   ${PROJ_LIBRARIES})
 add_test(NAME proj_context_test COMMAND proj_context_test)
 set_property(TEST proj_context_test
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 
 if(MSVC AND BUILD_LIBPROJ_SHARED)
   # ph_phi2_test not compatible of a .dll build
@@ -115,7 +115,7 @@ else()
     ${PROJ_LIBRARIES})
   add_test(NAME pj_phi2_test COMMAND pj_phi2_test)
   set_property(TEST pj_phi2_test
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 endif()
 
 add_executable(proj_test_cpp_api
@@ -135,7 +135,7 @@ target_link_libraries(proj_test_cpp_api
   ${SQLITE3_LIBRARY})
 add_test(NAME proj_test_cpp_api COMMAND proj_test_cpp_api)
 set_property(TEST proj_test_cpp_api
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 
 
 add_executable(gie_self_tests
@@ -146,7 +146,7 @@ target_link_libraries(gie_self_tests
   ${PROJ_LIBRARIES})
 add_test(NAME gie_self_tests COMMAND gie_self_tests)
 set_property(TEST gie_self_tests
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data")
 
 
 add_executable(test_network
@@ -163,8 +163,8 @@ target_link_libraries(test_network
 add_test(NAME test_network COMMAND test_network)
 if(MSVC)
     set_property(TEST test_network
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data\\;${PROJECT_SOURCE_DIR}/data;PROJ_SOURCE_DATA=${PROJECT_SOURCE_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data\\;${PROJECT_SOURCE_DIR}/data;PROJ_SOURCE_DATA=${PROJECT_SOURCE_DIR}/data")
 else()
     set_property(TEST test_network
-        PROPERTY ENVIRONMENT "PROJ_LIB=${PROJECT_BINARY_DIR}/data:${PROJECT_SOURCE_DIR}/data;PROJ_SOURCE_DATA=${PROJECT_SOURCE_DIR}/data")
+        PROPERTY ENVIRONMENT "PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES;PROJ_LIB=${PROJECT_BINARY_DIR}/data:${PROJECT_SOURCE_DIR}/data;PROJ_SOURCE_DATA=${PROJECT_SOURCE_DIR}/data")
 endif()
diff --git a/test/unit/Makefile.am b/test/unit/Makefile.am
index 422fe687..7ffb06ae 100644
--- a/test/unit/Makefile.am
+++ b/test/unit/Makefile.am
@@ -23,7 +23,7 @@ pj_transform_test_SOURCES = pj_transform_test.cpp main.cpp
 pj_transform_test_LDADD = ../../src/libproj.la @GTEST_LIBS@
 
 pj_transform_test-check: pj_transform_test
-	PROJ_LIB=$(PROJ_LIB) ./pj_transform_test
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) ./pj_transform_test
 
 pj_phi2_test_SOURCES = pj_phi2_test.cpp main.cpp
 pj_phi2_test_LDADD = ../../src/libproj.la @GTEST_LIBS@
@@ -47,19 +47,19 @@ proj_context_test_SOURCES = proj_context_test.cpp main.cpp
 proj_context_test_LDADD = ../../src/libproj.la @GTEST_LIBS@
 
 proj_context_test-check: proj_context_test
-	./proj_context_test
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES ./proj_context_test
 
 test_cpp_api_SOURCES = test_util.cpp test_common.cpp test_crs.cpp test_metadata.cpp test_io.cpp test_operation.cpp test_datum.cpp test_factory.cpp test_c_api.cpp main.cpp
 test_cpp_api_LDADD = ../../src/libproj.la @GTEST_LIBS@ @SQLITE3_LIBS@
 
 test_cpp_api-check: test_cpp_api
-	PROJ_LIB=$(PROJ_LIB) ./test_cpp_api
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) ./test_cpp_api
 
 gie_self_tests_SOURCES = gie_self_tests.cpp main.cpp
 gie_self_tests_LDADD = ../../src/libproj.la @GTEST_LIBS@ @SQLITE3_LIBS@
 
 gie_self_tests-check: gie_self_tests
-	PROJ_LIB=$(PROJ_LIB) ./gie_self_tests
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) ./gie_self_tests
 
 include_proj_h_from_c_SOURCES = include_proj_h_from_c.c
 
@@ -68,6 +68,6 @@ test_network_CXXFLAGS = @CURL_CFLAGS@ @CURL_ENABLED_FLAGS@
 test_network_LDADD = ../../src/libproj.la @GTEST_LIBS@ @SQLITE3_LIBS@ @CURL_LIBS@
 
 test_network-check: test_network
-	PROJ_LIB=$(PROJ_LIB) PROJ_SOURCE_DATA=$(PROJ_LIB) ./test_network
+	PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES PROJ_LIB=$(PROJ_LIB) PROJ_SOURCE_DATA=$(PROJ_LIB) ./test_network
 
 check-local: pj_transform_test-check pj_phi2_test-check proj_errno_string_test-check proj_angular_io_test-check proj_context_test-check test_cpp_api-check gie_self_tests-check test_network-check
diff --git a/test/unit/gie_self_tests.cpp b/test/unit/gie_self_tests.cpp
index a738db75..a3b41fb0 100644
--- a/test/unit/gie_self_tests.cpp
+++ b/test/unit/gie_self_tests.cpp
@@ -348,7 +348,9 @@ TEST(gie, info_functions) {
 
     /* proj_info()                                                            */
     /* this one is difficult to test, since the output changes with the setup */
+    putenv(const_cast<char *>("PROJ_IGNORE_USER_WRITABLE_DIRECTORY="));
     info = proj_info();
+    putenv(const_cast<char *>("PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES"));
 
     if (info.version[0] != '\0') {
         char tmpstr[64];
@@ -360,6 +362,8 @@ TEST(gie, info_functions) {
         ASSERT_NE(std::string(info.searchpath), std::string());
     }
 
+    ASSERT_TRUE(std::string(info.searchpath).find("/proj") != std::string::npos);
+
     /* proj_pj_info() */
     {
         P = proj_create(PJ_DEFAULT_CTX,
diff --git a/test/unit/proj_context_test.cpp b/test/unit/proj_context_test.cpp
index 23c46f29..ec59590d 100644
--- a/test/unit/proj_context_test.cpp
+++ b/test/unit/proj_context_test.cpp
@@ -40,7 +40,20 @@
 
 namespace {
 
-static std::string createTempDict(std::string &dirname) {
+static bool createTmpFile(const std::string &filename) {
+    FILE *f = fopen(filename.c_str(), "wt");
+    if (!f)
+        return false;
+    fprintf(
+        f,
+        "<MY_PIPELINE> +proj=pipeline +step +proj=utm +zone=31 +ellps=GRS80\n");
+    fclose(f);
+    return true;
+}
+
+// ---------------------------------------------------------------------------
+
+static std::string createTempDict(std::string &dirname, const char *filename) {
     const char *temp_dir = getenv("TEMP");
     if (!temp_dir) {
         temp_dir = getenv("TMP");
@@ -58,16 +71,9 @@ static std::string createTempDict(std::string &dirname) {
     std::string tmpFilename;
     tmpFilename = temp_dir;
     tmpFilename += DIR_CHAR;
-    tmpFilename += "temp_proj_dic";
+    tmpFilename += filename;
 
-    FILE *f = fopen(tmpFilename.c_str(), "wt");
-    if (!f)
-        return std::string();
-    fprintf(
-        f,
-        "<MY_PIPELINE> +proj=pipeline +step +proj=utm +zone=31 +ellps=GRS80\n");
-    fclose(f);
-    return tmpFilename;
+    return createTmpFile(tmpFilename) ? tmpFilename : std::string();
 }
 
 // ---------------------------------------------------------------------------
@@ -85,7 +91,7 @@ static int MyUnlink(const std::string &filename) {
 TEST(proj_context, proj_context_set_file_finder) {
 
     std::string dirname;
-    auto filename = createTempDict(dirname);
+    auto filename = createTempDict(dirname, "temp_proj_dic1");
     if (filename.empty())
         return;
 
@@ -111,7 +117,7 @@ TEST(proj_context, proj_context_set_file_finder) {
     finderData.dirname = dirname;
     proj_context_set_file_finder(ctx, finder, &finderData);
 
-    auto P = proj_create(ctx, "+init=temp_proj_dic:MY_PIPELINE");
+    auto P = proj_create(ctx, "+init=temp_proj_dic1:MY_PIPELINE");
     EXPECT_NE(P, nullptr);
     proj_destroy(P);
 
@@ -125,7 +131,7 @@ TEST(proj_context, proj_context_set_file_finder) {
 TEST(proj_context, proj_context_set_search_paths) {
 
     std::string dirname;
-    auto filename = createTempDict(dirname);
+    auto filename = createTempDict(dirname, "temp_proj_dic2");
     if (filename.empty())
         return;
 
@@ -134,7 +140,7 @@ TEST(proj_context, proj_context_set_search_paths) {
     const char *path = dirname.c_str();
     proj_context_set_search_paths(ctx, 1, &path);
 
-    auto P = proj_create(ctx, "+init=temp_proj_dic:MY_PIPELINE");
+    auto P = proj_create(ctx, "+init=temp_proj_dic2:MY_PIPELINE");
     EXPECT_NE(P, nullptr);
     proj_destroy(P);
 
@@ -143,4 +149,32 @@ TEST(proj_context, proj_context_set_search_paths) {
     MyUnlink(filename);
 }
 
+// ---------------------------------------------------------------------------
+
+TEST(proj_context, read_grid_from_user_writable_directory) {
+
+    auto ctx = proj_context_create();
+    auto path = pj_context_get_user_writable_directory(ctx, true);
+    EXPECT_TRUE(!path.empty());
+    auto filename = path + DIR_CHAR + "temp_proj_dic3";
+    EXPECT_TRUE(createTmpFile(filename));
+    {
+        // Check that with PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES (set by
+        // calling script), we cannot find the file
+        auto P = proj_create(ctx, "+init=temp_proj_dic3:MY_PIPELINE");
+        EXPECT_EQ(P, nullptr);
+        proj_destroy(P);
+    }
+    {
+        // Cancel the effect of PROJ_IGNORE_USER_WRITABLE_DIRECTORY
+        putenv(const_cast<char *>("PROJ_IGNORE_USER_WRITABLE_DIRECTORY="));
+        auto P = proj_create(ctx, "+init=temp_proj_dic3:MY_PIPELINE");
+        EXPECT_NE(P, nullptr);
+        putenv(const_cast<char *>("PROJ_IGNORE_USER_WRITABLE_DIRECTORY=YES"));
+        proj_destroy(P);
+    }
+    proj_context_destroy(ctx);
+    MyUnlink(filename);
+}
+
 } // namespace