Get Tcl_Init() working for Tcl9, the major caveat being that for statically-linked builds this only works if the Tcl9 main lib ZIP file (part of its source build but not installed) gets concatenated to the resulting custom shell's binary. Thanks to Jan Nijtmans for his help with this.

FossilOrigin-Name: 404bf0d76ce01d07046cf1fa42b45a72e3b62e292e0fa3c0c4d75beb4a4d6885

manifest

@@ -1,5 +1,5 @@
-C Merge\strunk\sinto\stcl-init\sbranch.
-D 2025-08-28T12:04:24.366
+C Get\sTcl_Init()\sworking\sfor\sTcl9,\sthe\smajor\scaveat\sbeing\sthat\sfor\sstatically-linked\sbuilds\sthis\sonly\sworks\sif\sthe\sTcl9\smain\slib\sZIP\sfile\s(part\sof\sits\ssource\sbuild\sbut\snot\sinstalled)\sgets\sconcatenated\sto\sthe\sresulting\scustom\sshell's\sbinary.\sThanks\sto\sJan\sNijtmans\sfor\shis\shelp\swith\sthis.
+D 2025-08-28T14:21:18.899
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -750,7 +750,7 @@ F src/sqliteInt.h 27c73e48878d31ef230ba867d1f8c3af6aed357fd93ccc605d3f1aae007ea6
 F src/sqliteLimit.h fe70bd8983e5d317a264f2ea97473b359faf3ebb0827877a76813f5cf0cdc364
 F src/status.c 0e72e4f6be6ccfde2488eb63210297e75f569f3ce9920f6c3d77590ec6ce5ffd
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
-F src/tclsqlite.c c3c31f4e8c2506d356d1439fa57d922cb0a25831491837dad3bf74abf8965d84
+F src/tclsqlite.c 43db3e50e674d715fce53957d6607f8833a261f1e241d3df5647bd789cdeac5d
 F src/tclsqlite.h 614b3780a62522bc9f8f2b9fb22689e8009958e7aa77e572d0f3149050af348a
 F src/test1.c 82d8aab7162a758d030728cab6ae6011785234854b7d6d2aebd877f985d1016a
 F src/test2.c 62f0830958f9075692c29c6de51b495ae8969e1bef85f239ffcd9ba5fb44a5ff
@@ -2171,8 +2171,8 @@ F tool/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd7227350
 F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
 F tool/warnings.sh 1ad0169b022b280bcaaf94a7fa231591be96b514230ab5c98fbf15cd7df842dd
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 9eb5c91c897f8820affb30f8571eb927423c7831161f5df0043715e7f0a729d7 6bf54bbc4d503e8ebeb804dfb318383770e85d434dacbbbd8f6dadc7595b1856
-R b8ab2b652bc2f13b08ccb29fd908e6b3
+P 64c802ca1057ba538d9132ddcdda40f9452c80fac8ec1468661c34174c65db7f
+R bb6ccca120a51cf92d1112a6136bf4a8
 U stephan
-Z 1e97fd690c7294fd8e0391a007db7353
+Z 8a9eb4a5089b199530be54b854c32f89
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-64c802ca1057ba538d9132ddcdda40f9452c80fac8ec1468661c34174c65db7f
+404bf0d76ce01d07046cf1fa42b45a72e3b62e292e0fa3c0c4d75beb4a4d6885

src/tclsqlite.c

@@ -4187,7 +4187,16 @@ int SQLITE_CDECL TCLSH_MAIN(int argc, char **argv){
   sqlite3_shutdown();
 
   Tcl_FindExecutable(argv[0]);
+#if TCL_MAJOR_VERSION > 8 && (!defined(_WIN32) || defined(UNICODE))
+  /* Tcl 9.0. Does not work on Windows without UNICODE because it
+  ** requires a WCHAR string for argv[0] here.  Also, for
+  ** statically-linked tcl9 this only works if this binary has tcl9's
+  ** main library ZIP file attached to it somehow (and the canonical
+  ** build does not do that). */
+  TclZipfs_AppHook(&argc, &argv);
+#endif
   Tcl_SetSystemEncoding(NULL, "utf-8");
+
   interp = Tcl_CreateInterp();
   Sqlite3_Init(interp);
   Tcl_Init(interp);