8286562: GCC 12 reports some compiler warnings

src/java.base/share/native/libjli/java.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1995, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1626,7 +1626,7 @@ TranslateApplicationArgs(int jargc, const char **jargv, int *pargc, char ***parg
     for (i = 0; i < jargc; i++) {
         const char *arg = jargv[i];
         if (arg[0] == '-' && arg[1] == 'J') {
-            *nargv++ = (arg[2] == '\0') ? NULL : JLI_StringDup(arg + 2);
+            *nargv++ = ((arg + 2) == NULL) ? NULL : JLI_StringDup(arg + 2);
         }
     }
 

src/java.base/share/native/libjli/parse_manifest.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -288,8 +288,8 @@ find_positions(int fd, Byte *eb, jlong* base_offset, jlong* censtart)
     for (cp = &buffer[bytes - ENDHDR]; cp >= &buffer[0]; cp--)
         if (ENDSIG_AT(cp) && (cp + ENDHDR + ENDCOM(cp) == endpos)) {
             (void) memcpy(eb, cp, ENDHDR);
-            pos = flen - (endpos - cp);
             free(buffer);
+            pos = flen - (endpos - cp);
             return find_positions64(fd, eb, pos, base_offset, censtart);
         }
     free(buffer);

src/jdk.jpackage/linux/native/applauncher/LinuxPackage.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,7 +25,6 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <stddef.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <linux/limits.h>
@@ -124,7 +123,6 @@ static int popenCommand(const char* cmdlineFormat, const char* arg,
     int callbackMode = POPEN_CALLBACK_USE;
     int exitCode = -1;
     int c;
-    ptrdiff_t char_offset;
 
     cmdline = malloc(cmdlineLenth + 1 /* \0 */);
     if (!cmdline) {
@@ -173,14 +171,13 @@ static int popenCommand(const char* cmdlineFormat, const char* arg,
         if (strBufNextChar == strBufEnd) {
             /* Double buffer size */
             strBufCapacity = strBufCapacity * 2 + 1;
-            char_offset = strBufNextChar - strBufBegin;
             strNewBufBegin = realloc(strBufBegin, strBufCapacity);
             if (!strNewBufBegin) {
                 JP_LOG_ERRNO;
                 goto cleanup;
             }
 
-            strBufNextChar = strNewBufBegin + char_offset;
+            strBufNextChar = strNewBufBegin + (strBufNextChar - strBufBegin);
             strBufEnd = strNewBufBegin + strBufCapacity;
             strBufBegin = strNewBufBegin;
         }