Merge RFC4 (#1865)

This commit is the result of the squashing of rfc4_dev branch in a single
commit. It implements mostly RFC 4 related work.

* Grid handling:
  - remove obsolete and presumably unfinished implementation of grid catalog functionality
  - all grid functionality is in grids.cpp/.hpp
  - vertical and horizontal grid shift: rework to no longer load whole grid into memory
  - remove hgrids and vgrids member from PJ structure, and store them in hgridshift/vgridshift/deformation structures
  - build systems: add optional libtiff dependency. Must be explicitly disabled if not desired
  - add support for horizontal and vertical grids in GeoTIFF, if libtiff is available
  - add GenericShiftGridSet and GenericShiftGrid classes, relying on TIFF grids, that can be used for generic purpose grid-based adjustment
  - add a +proj=xyzgridshift method to perform geocentric translation by grid. Used for French NTF to RGF93 transformation using gr3df97a.tif grid
  - deformation: add support for +grids= for GeoTIFF grids
  - horizontal grid shift: fix failures on points slightly outside a subgrid (fixes #209)

* File management:
  - add a filemanager.cpp/.hpp to deal with file related work
  - test for legacy proj_api.h fileapi
  - proj.h: add proj_context_set_fileapi() and proj_context_set_sqlite3_vfs_name() (fixes #866)
  - add capability to read resource files from the user writable directory

* Network access:
  - build systems: add optional curl dependency
  - add a curl-based default implementation for network related functionality
  - proj.h: add C API to control network functionality, and optionaly provide network callbacks
  - add data/proj.ini with default settings
  - add a SQLite3 local cache of downloaded chunks
  - add proj_is_download_needed() and proj_download_file()

* Use Win32 Unicode APIs and expect all strings to be UTF-8 (fixes #1765)
  For backward compatibility, if PROJ_LIB content is found to be not UTF-8 or
  pointing to a non existing directory, then an attempt at interpretating it
  in the ANSI page encoding is done.
  proj_context_set_search_paths() now assumes strings to be in UTF-8, and
  functions returning paths will also return values in UTF-8.

1 files changed, 49 insertions, 14 deletions

diff --git a/test/unit/proj_context_test.cpp b/test/unit/proj_context_test.cpp
index 23c46f29..92f251cd 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 +149,33 @@ 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_SKIP_READ_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_SKIP_READ_USER_WRITABLE_DIRECTORY
+        putenv(const_cast<char *>("PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY="));
+        auto P = proj_create(ctx, "+init=temp_proj_dic3:MY_PIPELINE");
+        EXPECT_NE(P, nullptr);
+        putenv(
+            const_cast<char *>("PROJ_SKIP_READ_USER_WRITABLE_DIRECTORY=YES"));
+        proj_destroy(P);
+    }
+    proj_context_destroy(ctx);
+    MyUnlink(filename);
+}
+
 } // namespace