Enhance qemuParseCommandLineKeywords

Current version expects name=value,... list and when an incorrect string
such as "a,b,c=d" would be parsed as "a,b,c" keyword with "d" value
without reporting any error, which is probably not the expected
behavior.

This patch adds an extra argument called allowEmptyValue, which if
non-zero will permit keywords with no value; "a,b=c,,d=" will be parsed
as follows:
    keyword value
    "a"     NULL
    "b"     "c"
    ""      NULL
    "d"     ""

In case allowEmptyValue is zero, the string is required to contain
name=value pairs only; retvalues is guaranteed to contain non-NULL
pointers. Now, "a,b,c=d" will result in an error.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_conf.c

@@ -3928,47 +3928,58 @@ static const char *qemuFindEnv(const char **progenv,
 /*
  * Takes a string containing a set of key=value,key=value,key...
  * parameters and splits them up, returning two arrays with
- * the individual keys and values
+ * the individual keys and values. If allowEmptyValue is nonzero,
+ * the "=value" part is optional and if a key with no value is found,
+ * NULL is be placed into corresponding place in retvalues.
  */
 static int
 qemuParseCommandLineKeywords(virConnectPtr conn,
                              const char *str,
                              char ***retkeywords,
-                             char ***retvalues)
+                             char ***retvalues,
+                             int allowEmptyValue)
 {
     int keywordCount = 0;
     int keywordAlloc = 0;
     char **keywords = NULL;
     char **values = NULL;
     const char *start = str;
+    const char *end;
     int i;
 
     *retkeywords = NULL;
     *retvalues = NULL;
+    end = start + strlen(str);
 
     while (start) {
         const char *separator;
         const char *endmark;
         char *keyword;
-        char *value;
+        char *value = NULL;
 
-        if (!(separator = strchr(start, '='))) {
-            qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR,
-                             _("malformed keyword arguments in '%s'"), str);
-            goto error;
+        if (!(endmark = strchr(start, ',')))
+            endmark = end;
+        if (!(separator = strchr(start, '=')))
+            separator = end;
+
+        if (separator >= endmark) {
+            if (!allowEmptyValue) {
+                qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR,
+                                 _("malformed keyword arguments in '%s'"), str);
+                goto error;
+            }
+            separator = endmark;
         }
+
         if (!(keyword = strndup(start, separator - start)))
             goto no_memory;
 
-        separator++;
-        endmark = strchr(separator, ',');
-
-        value = endmark ?
-            strndup(separator, endmark - separator) :
-            strdup(separator);
-        if (!value) {
-            VIR_FREE(keyword);
-            goto no_memory;
+        if (separator < endmark) {
+            separator++;
+            if (!(value = strndup(separator, endmark - separator))) {
+                VIR_FREE(keyword);
+                goto no_memory;
+            }
         }
 
         if (keywordAlloc == keywordCount) {
@@ -3985,7 +3996,7 @@ qemuParseCommandLineKeywords(virConnectPtr conn,
         values[keywordCount] = value;
         keywordCount++;
 
-        start = endmark ? endmark + 1 : NULL;
+        start = endmark < end ? endmark + 1 : NULL;
     }
 
     *retkeywords = keywords;
@@ -4028,7 +4039,7 @@ qemuParseCommandLineDisk(virConnectPtr conn,
 
     if ((nkeywords = qemuParseCommandLineKeywords(conn, val,
                                                   &keywords,
-                                                  &values)) < 0)
+                                                  &values, 0)) < 0)
         return NULL;
 
     if (VIR_ALLOC(def) < 0) {
@@ -4254,7 +4265,7 @@ qemuParseCommandLineNet(virConnectPtr conn,
         if ((nkeywords = qemuParseCommandLineKeywords(conn,
                                                       tmp+1,
                                                       &keywords,
-                                                      &values)) < 0)
+                                                      &values, 0)) < 0)
             return NULL;
     } else {
         nkeywords = 0;
@@ -4327,7 +4338,7 @@ qemuParseCommandLineNet(virConnectPtr conn,
         if ((nkeywords = qemuParseCommandLineKeywords(conn,
                                                       nic + strlen("nic,"),
                                                       &keywords,
-                                                      &values)) < 0) {
+                                                      &values, 0)) < 0) {
             virDomainNetDefFree(def);
             def = NULL;
             goto cleanup;