Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -5050,7 +5050,10 @@
   for (QualType ParamType : FT->param_types()) {
 
     // Convert array arguments to pointer to simplify type lookup.
-    Expr *Arg = Sema->DefaultFunctionArrayLvalueConversion(ArgExprs[i++]).get();
+    ExprResult R = Sema->DefaultFunctionArrayLvalueConversion(ArgExprs[i++]);
+    if (R.isInvalid())
+      continue;
+    Expr *Arg = R.get();
     QualType ArgType = Arg->getType();
     if (!ParamType->isPointerType() ||
         ParamType.getQualifiers().hasAddressSpace() ||
Index: test/Sema/implicit-function-typo-crash.c
===================================================================
--- /dev/null
+++ test/Sema/implicit-function-typo-crash.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+// PR25961
+void free(); // expected-note {{'free' declared here}}
+int main() {
+  strcpy(file, 0); // expected-warning {{implicitly declaring library function 'strcpy' with type}} \
+  // expected-note {{include the header <string.h>}} \
+  // expected-error {{use of undeclared identifier 'file'; did you mean 'free'}}
+}