utils: prefer shlib when looking through unixodbc installations

Author: detule

R/utils.R

@@ -375,37 +375,48 @@ locate_install_unixodbc <- function() {
     "/opt/R/x86_64/lib"
   )
 
-  list.files(
-    common_dirs,
-    pattern = libodbcinst_filename(),
-    full.names = TRUE
-  )
+  file_names <- libodbcinst_filename()
+  for (file_name in file_names) {
+    paths <- list.files(
+       common_dirs,
+       pattern = file_name,
+       full.names = TRUE
+    )
+    if (length(paths)) {
+      return(paths)
+    }
+  }
+  return(character())
 }
 
 system_safely <- function(x) {
   tryCatch(
     {
       unixodbc_prefix <- system(x, intern = TRUE, ignore.stderr = TRUE)
-      candidates <- list.files(unixodbc_prefix,
-        pattern = libodbcinst_filename(), full.names = TRUE)
-      if (!length(candidates)) {
-        stop("Unable to locate unixodbc using odbc_config")
+      file_names <- libodbcinst_filename()
+      for (file_name in file_names) {
+        candidates <- list.files(unixodbc_prefix,
+          pattern = file_name, full.names = TRUE)
+        if (length(candidates)) {
+          return(candidates[1])
+        }
       }
-      return(candidates[1])
+      stop("Unable to locate unixodbc using odbc_config")
     },
     error = function(e) {},
     warning = function(w) {}
   )
   character()
 }
 
-# Returns a pattern to be used with
-# list.files( ..., pattern = ... ).
+# Returns a vector of possible lib filenames.
+# Vector is ordered and should be iterated over
+# in same order.
 libodbcinst_filename <- function() {
   if (is_macos()) {
-    "libodbcinst.dylib|libodbcinst.a"
+    return(c("libodbcinst.dylib", "libodbcinst.a"))
   } else {
-    "libodbcinst.so|libodbcinst.a"
+    return(c("libodbcinst.so", "libodbcinst.a"))
   }
 }
 

tests/testthat/test-utils.R

@@ -214,6 +214,50 @@ test_that("locate_install_unixodbc() returns reasonable values", {
   expect_true(grepl("(\\.dylib|\\.a)$", res[1]))
 })
 
+# https://github.com/r-dbi/odbc/issues/919
+test_that("locate_install_unixodbc() prefers shlib", {
+  # odbc_config / pkg-config cflags point to nonexistent files on CRAN (#903)
+  skip_on_cran()
+  {
+    local_mocked_bindings(
+      is_macos = function() {TRUE},
+      list.files = function (path = ".", pattern = NULL, all.files = FALSE, full.names = FALSE, ...) {
+        # Mimic being able to find any pattern passed as argument
+        return(pattern)
+      }
+    )
+    res <- locate_install_unixodbc()
+    expect_equal(length(res), 1)
+    expect_true(grepl("(\\.dylib)$", res[1]))
+  }
+  {
+    local_mocked_bindings(
+      is_macos = function() {TRUE},
+      list.files = function (path = ".", pattern = NULL, all.files = FALSE, full.names = FALSE, ...) {
+        # Mimic being able to find .a only
+        if(pattern == "libodbcinst.a") return(pattern)
+        return(character())
+      }
+    )
+    res <- locate_install_unixodbc()
+    expect_equal(length(res), 1)
+    expect_true(grepl("(\\.a)$", res[1]))
+  }
+  {
+    local_mocked_bindings(
+      is_macos = function() {TRUE},
+      list.files = function (path = ".", pattern = NULL, all.files = FALSE, full.names = FALSE, ...) {
+        # Mimic being able to find shlib only
+        if(pattern == "libodbcinst.dylib") return(pattern)
+        return(character())
+      }
+    )
+    res <- locate_install_unixodbc()
+    expect_equal(length(res), 1)
+    expect_true(grepl("(\\.dylib)$", res[1]))
+  }
+})
+
 test_that("databricks() errors informatively when spark ini isn't writeable", {
   local_mocked_bindings(is_writeable = function(path) {FALSE})
   expect_snapshot(