Fix off-by-one error when emitting diagnostics. Also, make diagnostic

a bit nicer for people who pass lots of extra arguments to calls by 
selecting them all instead of just the first one:

arg-duplicate.c:13:13: error: too many arguments to function
  f3 (1, 1, 2, 3, 4);   // expected-error {{too many arguments to function}}
            ^~~~~~~

This implements test/Sema/arg-duplicate.c, thanks to Neil for pointing
out this crash.

llvm-svn: 40136

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/Sema/arg-duplicate.c b/clang/test/Sema/arg-duplicate.c
new file mode 100644
index 00000000000..5d44a72ecb3
--- /dev/null
+++ b/clang/test/Sema/arg-duplicate.c
@@ -0,0 +1,15 @@
+// RUN: clang -parse-ast-check %s
+
+typedef int x; 
+int f3(y, x, 
+       x)          // expected-error {{redefinition of parameter}}
+  int y, x, 
+      x;           // expected-error {{redefinition of parameter}}
+{
+  return x + y; 
+} 
+
+void f4(void) { 
+  f3 (1, 1, 2, 3, 4);   // expected-error {{too many arguments to function}}
+}
+