[Qemu-devel] [PATCH 1/7] qemu-img create: Detect options specified more than once

[Kevin Wolf <kwolf@redhat.com>]

If you specified multiple -o options for qemu-img create, it would
silently ignore all but the last one. Similarly, for other options the
last occurence wins (which is at least a bit less surprising). Error out
instead.

The only exception is a -o help option, which may be added to any valid
qemu-img create command and ignores all other options.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-img.c | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index c989850..6a64fe1 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -341,13 +341,14 @@ static int img_create(int argc, char **argv)
 {
     int c;
     uint64_t img_size = -1;
-    const char *fmt = "raw";
+    const char *fmt = NULL;
     const char *base_fmt = NULL;
     const char *filename;
     const char *base_filename = NULL;
     char *options = NULL;
     Error *local_err = NULL;
     bool quiet = false;
+    bool options_help = false;
 
     for(;;) {
         c = getopt(argc, argv, "F:b:f:he6o:q");
@@ -360,12 +361,24 @@ static int img_create(int argc, char **argv)
             help();
             break;
         case 'F':
+            if (base_fmt) {
+                error_report("-F may only be specified once");
+                return 1;
+            }
             base_fmt = optarg;
             break;
         case 'b':
+            if (base_filename) {
+                error_report("-b may only be specified once");
+                return 1;
+            }
             base_filename = optarg;
             break;
         case 'f':
+            if (fmt) {
+                error_report("-f may only be specified once");
+                return 1;
+            }
             fmt = optarg;
             break;
         case 'e':
@@ -377,7 +390,16 @@ static int img_create(int argc, char **argv)
                   "compat6\' instead!");
             return 1;
         case 'o':
-            options = optarg;
+            if (is_help_option(optarg)) {
+                options_help = true;
+            } else if (!options) {
+                options = optarg;
+            } else {
+                error_report("-o cannot be used multiple times. Please use a "
+                             "single -o option with comma-separated settings "
+                             "instead.");
+                return 1;
+            }
             break;
         case 'q':
             quiet = true;
@@ -385,6 +407,10 @@ static int img_create(int argc, char **argv)
         }
     }
 
+    if (!fmt) {
+        fmt = "raw";
+    }
+
     /* Get the filename */
     if (optind >= argc) {
         help();
@@ -413,7 +439,7 @@ static int img_create(int argc, char **argv)
         help();
     }
 
-    if (options && is_help_option(options)) {
+    if (options_help) {
         return print_block_option_help(filename, fmt);
     }
 
-- 
1.8.1.4