diff --git a/Makefile.in b/Makefile.in
index 5ee6a09..2c50768 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -572,7 +572,9 @@
 # Extra compiler options for various shell tools
 #
 SHELL_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS4
+# SHELL_OPT += -DSQLITE_ENABLE_FTS5
 SHELL_OPT += -DSQLITE_ENABLE_EXPLAIN_COMMENTS
+SHELL_OPT += -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
 FUZZERSHELL_OPT = -DSQLITE_ENABLE_JSON1
 FUZZCHECK_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5
 
diff --git a/Makefile.msc b/Makefile.msc
index cd866ce..8e54f53 100644
--- a/Makefile.msc
+++ b/Makefile.msc
@@ -1395,7 +1395,10 @@
 # when the shell is not being dynamically linked.
 #
 !IF $(DYNAMIC_SHELL)==0 && $(FOR_WIN10)==0
-SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_SHELL_JSON1 -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_EXPLAIN_COMMENTS
+SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_SHELL_JSON1 -DSQLITE_ENABLE_FTS4
+# SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_FTS5
+SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_EXPLAIN_COMMENTS
+SHELL_COMPILE_OPTS = $(SHELL_COMPILE_OPTS) -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
 !ENDIF
 
 # <<mark>>
diff --git a/main.mk b/main.mk
index 5cb393b..c8754c7 100644
--- a/main.mk
+++ b/main.mk
@@ -458,6 +458,8 @@
 # Extra compiler options for various shell tools
 #
 SHELL_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_FTS5
+SHELL_OPT += -DSQLITE_ENABLE_EXPLAIN_COMMENTS
+SHELL_OPT += -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
 FUZZERSHELL_OPT = -DSQLITE_ENABLE_JSON1
 FUZZCHECK_OPT = -DSQLITE_ENABLE_JSON1 -DSQLITE_ENABLE_MEMSYS5
 
diff --git a/manifest b/manifest
index 4a8ab43..c58ca8c 100644
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
-C Merge\srecent\strunk\sfixes.
-D 2016-07-28T18:42:21.282
-F Makefile.in 7ac1f34182d307765c6439c899bd3dac2af587bf
+C Add\san\sexperimental\sSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION\scompile-time\soption.\nWhen\senabled,\sthe\s"unknown\sfunction"\serror\sis\ssuppressed\sfor\sEXPLAIN\sand\na\sno-op\sfunction\snamed\s"unknown"\sis\ssubstituted.\s\sThis\sfacilitiates\susing\nthe\scommand-line\sshell\sto\sanalyze\squeries\sfrom\sapplications\sthat\scontain\nmany\sapplication-defined\sfunctions\sthat\sare\snot\snormally\savailable\sto\sthe\nshell.
+D 2016-08-04T01:47:01.678
+F Makefile.in b0c3cd9e30ffb18d6952dbf3c2ee5ae07c6216d4
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
-F Makefile.msc d66d0395c38571aab3804f8db0fa20707ae4609a
+F Makefile.msc c5b2eca5bdf5f73fe9eebf78f07755e2509fd629
 F README.md 8ecc12493ff9f820cdea6520a9016001cb2e59b7
 F VERSION cb29eb11e493dd85b3eeec4053c03949bf98478e
 F aclocal.m4 a5c22d164aff7ed549d53a90fa56d56955281f50
@@ -311,7 +311,7 @@
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
 F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
 F magic.txt 8273bf49ba3b0c8559cb2774495390c31fd61c60
-F main.mk 6c503ea04b21085b03cd56de80412da2646ff1e5
+F main.mk af15e89c810547dc18d23020451e2d75effaf21c
 F mkso.sh fd21c06b063bb16a5d25deea1752c2da6ac3ed83
 F mptest/config01.test 3c6adcbc50b991866855f1977ff172eb6d901271
 F mptest/config02.test 4415dfe36c48785f751e16e32c20b077c28ae504
@@ -340,10 +340,10 @@
 F src/date.c 1cc9fb516ec9932c6fd4d2a0d2f8bc4480145c39
 F src/dbstat.c 4f6f7f52b49beb9636ffbd517cfe44a402ba4ad0
 F src/delete.c 4aba4214a377ce8ddde2d2e609777bcc8235200f
-F src/expr.c fbc17c717a80b5b61158ea8f25b5af6f8cad66f8
+F src/expr.c 9c5eca8602f6c496e8d4eefefe2aae3d831dd510
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c bc4145347595b7770f9a598cff1c848302cf5413
-F src/func.c 61a4114cf7004f10c542cfabbab9f2bcb9033045
+F src/func.c 29cc9acb170ec1387b9f63eb52cd85f8de96c771
 F src/global.c c45ea22aff29334f6a9ec549235ac3357c970015
 F src/hash.c 55b5fb474100cee0b901edaf203e26c970940f36
 F src/hash.h ab34c5c54a9e9de2e790b24349ba5aab3dbb4fd4
@@ -384,7 +384,7 @@
 F src/prepare.c 9c56ea254317e27d3a1273fa812b8578b5e2f850
 F src/printf.c a5f0ca08ddede803c241266abb46356ec748ded1
 F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
-F src/resolve.c cca3aa77b95706df5d635a2141a4d1de60ae6598
+F src/resolve.c 0392c6686586b1d4dac9a4106959f03ddd70e9aa
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
 F src/select.c f3c6e9065fb34f6a23af27ec7f1f717ffbfc2ee4
 F src/shell.c 9351fc6de11e1d908648c0a92d85627138e3dee5
@@ -1513,7 +1513,10 @@
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 91e811f51e611a37372875e96a4c51bbed2dfdea 805d01cdabb48a69eb986a7f084e53eb25d76b7f
-R 1f1e8b1dc5bfb43f90c10984a7e1c85e
+P 97657445860363f5bd62c37e6a565e782e7eb908
+R c1b6454d8f71efcd1ab7fc64b6002698
+T *branch * unknown-function
+T *sym-unknown-function *
+T -sym-apple-osx *
 U drh
-Z 3d02145717de05c1fec9768a8381adbd
+Z 6495d62c822011f2ce59f727ab874d9c
diff --git a/manifest.uuid b/manifest.uuid
index f387980..9a6d819 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-97657445860363f5bd62c37e6a565e782e7eb908
\ No newline at end of file
+4ada023ca075628fdafc3bc4520239b9789cff29
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index c6d74cf..74f09bb 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2943,6 +2943,11 @@
       assert( !ExprHasProperty(pExpr, EP_IntValue) );
       zId = pExpr->u.zToken;
       pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+      if( pDef==0 && pParse->explain ){
+        pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);
+      }
+#endif
       if( pDef==0 || pDef->xFinalize!=0 ){
         sqlite3ErrorMsg(pParse, "unknown function: %s()", zId);
         break;
diff --git a/src/func.c b/src/func.c
index 78c8806..79bb1e3 100644
--- a/src/func.c
+++ b/src/func.c
@@ -1316,6 +1316,26 @@
 }
 
 
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+/*
+** The "unknown" function is automatically substituted in place of
+** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN
+** when the SQLITE_ENABLE_UNKNOWN_FUNCTION compile-time option is used.
+** When the "sqlite3" command-line shell is built using this functionality,
+** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries
+** involving application-defined functions to be examined in a generic
+** sqlite3 shell.
+*/
+static void unknownFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  /* no-op */
+}
+#endif /*SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION*/
+
+
 /* IMP: R-25361-16150 This function is omitted from SQLite by default. It
 ** is only available if the SQLITE_SOUNDEX compile-time option is used
 ** when SQLite is built.
@@ -1786,13 +1806,16 @@
     AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),
   
     LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
-  #ifdef SQLITE_CASE_SENSITIVE_LIKE
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
     LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
     LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
-  #else
+#else
     LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),
     LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
-  #endif
+#endif
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+    FUNCTION(unknown,           -1, 0, 0, unknownFunc      ),
+#endif
     FUNCTION(coalesce,           1, 0, 0, 0                ),
     FUNCTION(coalesce,           0, 0, 0, 0                ),
     FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
diff --git a/src/resolve.c b/src/resolve.c
index 77ce37f..8ae7f09 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -718,7 +718,11 @@
         sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
         pNC->nErr++;
         is_agg = 0;
-      }else if( no_such_func && pParse->db->init.busy==0 ){
+      }else if( no_such_func && pParse->db->init.busy==0
+#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
+                && pParse->explain==0
+#endif
+      ){
         sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
         pNC->nErr++;
       }else if( wrong_num_args ){