patch 9.0.0584: cscope test with wrong executable name fails

Problem:    Cscope test with wrong executable name fails.
Solution:   Use /bin/sh to execute the command. (Yegappan Lakshmanan)
diff --git a/src/if_cscope.c b/src/if_cscope.c
index 945b019..ad29fb9 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -799,7 +799,7 @@
 	return NULL;
     }
 
-    // Skip white space before the patter, except for text and pattern search,
+    // Skip white space before the pattern, except for text and pattern search,
     // they may want to use the leading white space.
     pat = pattern;
     if (search != 4 && search != 6)
@@ -825,6 +825,7 @@
 #ifdef UNIX
     int		to_cs[2], from_cs[2];
 #endif
+    int		cmdlen;
     int		len;
     char	*prog, *cmd, *ppath = NULL;
 #ifdef MSWIN
@@ -917,7 +918,7 @@
 	expand_env(p_csprg, (char_u *)prog, MAXPATHL);
 
 	// alloc space to hold the cscope command
-	len = (int)(strlen(prog) + strlen(csinfo[i].fname) + 32);
+	cmdlen = (int)(strlen(prog) + strlen(csinfo[i].fname) + 32);
 	if (csinfo[i].ppath)
 	{
 	    // expand the prepend path for env var's
@@ -933,13 +934,13 @@
 	    }
 	    expand_env((char_u *)csinfo[i].ppath, (char_u *)ppath, MAXPATHL);
 
-	    len += (int)strlen(ppath);
+	    cmdlen += (int)strlen(ppath);
 	}
 
 	if (csinfo[i].flags)
-	    len += (int)strlen(csinfo[i].flags);
+	    cmdlen += (int)strlen(csinfo[i].flags);
 
-	if ((cmd = alloc(len)) == NULL)
+	if ((cmd = alloc(cmdlen)) == NULL)
 	{
 	    vim_free(prog);
 	    vim_free(ppath);
@@ -952,17 +953,21 @@
 	}
 
 	// run the cscope command
-	(void)sprintf(cmd, "%s -dl -f %s", prog, csinfo[i].fname);
-
+#ifdef UNIX
+	vim_snprintf(cmd, cmdlen, "/bin/sh -c \"exec %s -dl -f %s\"",
+							prog, csinfo[i].fname);
+#else
+	vim_snprintf(cmd, cmdlen, "%s -dl -f %s", prog, csinfo[i].fname);
+#endif
 	if (csinfo[i].ppath != NULL)
 	{
-	    (void)strcat(cmd, " -P");
-	    (void)strcat(cmd, csinfo[i].ppath);
+	    len = STRLEN(cmd);
+	    vim_snprintf(cmd + len, cmdlen - len, " -P%s", csinfo[i].ppath);
 	}
 	if (csinfo[i].flags != NULL)
 	{
-	    (void)strcat(cmd, " ");
-	    (void)strcat(cmd, csinfo[i].flags);
+	    len = STRLEN(cmd);
+	    vim_snprintf(cmd + len, cmdlen - len, " %s", csinfo[i].flags);
 	}
 # ifdef UNIX
 	// on Win32 we still need prog