FindPostgreSQL: support version encoding used in pre-10 releases

With the 10.x release, PostgreSQL upstream started encoding the version
as `MMmmmm` where `M` is major and `m` is minor. Prior to that, `MMmmPP`
was used where `P` was the patch number. Detect this difference and
decode it based on the used encoding.

Fixes: #19912

1 files changed, 12 insertions, 3 deletions

diff --git a/Tests/FindPostgreSQL/Test/main.c b/Tests/FindPostgreSQL/Test/main.c
index 2cfeed0da2..a63377a256 100644
--- a/Tests/FindPostgreSQL/Test/main.c
+++ b/Tests/FindPostgreSQL/Test/main.c
@@ -5,10 +5,19 @@
 int main()
 {
   int version = PQlibVersion();
-  int major = version / 10000;
-  int minor = version % 10000;
   char version_string[100];
-  snprintf(version_string, sizeof(version_string), "%d.%d", major, minor);
+  // 9.x and older encoding.
+  if (version < 100000) {
+    int major = version / 10000;
+    int minor = version % 10000 / 100;
+    int patch = version % 100;
+    snprintf(version_string, sizeof(version_string), "%d.%d.%d", major, minor,
+             patch);
+  } else {
+    int major = version / 10000;
+    int minor = version % 10000;
+    snprintf(version_string, sizeof(version_string), "%d.%d", major, minor);
+  }
   printf("Found PostgreSQL version %s, expected version %s\n", version_string,
          CMAKE_EXPECTED_POSTGRESQL_VERSION);
   return strcmp(version_string, CMAKE_EXPECTED_POSTGRESQL_VERSION);