cc: correct handling of leading ·

R=ken2
CC=golang-dev
https://golang.org/cl/193081

src/cmd/cc/lex.c

@@ -196,7 +196,8 @@ compile(char *file, char **defs, int ndef)
 	int i, c, fd[2];
 	static int first = 1;
 
-	ofile = strdup(file);
+	ofile = alloc(strlen(file)+10);
+	strcpy(ofile, file);
 	p = utfrrune(ofile, pathchar());
 	if(p) {
 		*p++ = 0;
@@ -405,9 +406,9 @@ lookup(void)
 	int c, n;
 	char *r, *w;
 
-	if(symb[0] == 0xc2 && symb[1] == 0xb7) {
+	if((uchar)symb[0] == 0xc2 && (uchar)symb[1] == 0xb7) {
 		// turn leading · into ""·
-		memmove(symb+2, symb, w-symb);
+		memmove(symb+2, symb, strlen(symb)+1);
 		symb[0] = '"';
 		symb[1] = '"';
 	}

src/cmd/cc/lexbody

@@ -223,6 +223,13 @@ lookup(void)
 	int c, l;
 	char *r, *w;
 
+	if((uchar)symb[0] == 0xc2 && (uchar)symb[1] == 0xb7) {
+		// turn leading · into ""·
+		memmove(symb+2, symb, strlen(symb)+1);
+		symb[0] = '"';
+		symb[1] = '"';
+	}
+
 	// turn · into .
 	for(r=w=symb; *r; r++) {
 		if((uchar)*r == 0xc2 && (uchar)*(r+1) == 0xb7) {
@@ -232,12 +239,6 @@ lookup(void)
 			*w++ = *r;
 	}
 	*w++ = '\0';
-	if(symb[0] == '.') {
-		// turn leading . into "".
-		memmove(symb+2, symb, w-symb);
-		symb[0] = '"';
-		symb[1] = '"';
-	}
 
 	h = 0;
 	for(p=symb; c = *p; p++)