Fix MinGW-Bug #3520488

diff --git a/ChangeLog b/ChangeLog
index a96aa73..a4a0fed 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2012-04-23  Keith Marshall  <keithmarshall@users.sourceforge.net>
+
+       Fix MinGW-Bug #3520488
+
+       * src/pkgexec.cpp (action_code): Check for, and reject NULL pointer
+       passed as action request string; also reject ambiguous abbreviations.
+
+       * src/climain.cpp (climain): Discriminate between NULL pointer and
+       other forms of invalid action keyword matching failures.
+
 2012-04-16  Keith Marshall  <keithmarshall@users.sourceforge.net>
 
        mingw-get-0.5-beta-20120416-1 released.

diff --git a/src/climain.cpp b/src/climain.cpp
index 34f30a8..8d575db 100644 (file)
--- a/src/climain.cpp
+++ b/src/climain.cpp
@@ -155,11 +155,22 @@ EXTERN_C int climain( int argc, char **argv )
      */
     int action = action_code( *argv );
     if( action < 0 )
-      /*
-       * The specified action keyword was invalid;
-       * force an abort through a DMH_FATAL notification...
+    {
+      /* No valid action keyword was found; force an abort
+       * through an appropriate DMH_FATAL notification...
        */
-      dmh_notify( DMH_FATAL, "%s: unknown action keyword\n", *argv );
+      if( *argv == NULL )
+       /*
+        * ...viz. the user didn't specify any argument, which
+        * could have been interpreted as an action keyword.
+        */
+       dmh_notify( DMH_FATAL, "no action specified\n" );
+
+      else
+       /* ...or, the specified action keyword was invalid.
+        */
+       dmh_notify( DMH_FATAL, "%s: unknown action keyword\n", *argv );
+    }
 
     /* If we get to here, then the specified action identifies a
      * valid operation; load the package database, according to the

diff --git a/src/pkgexec.cpp b/src/pkgexec.cpp
index 52970c0..68bb02e 100644 (file)
--- a/src/pkgexec.cpp
+++ b/src/pkgexec.cpp
@@ -68,23 +68,39 @@ EXTERN_C int action_code( const char* request )
   /* Match an action keyword specified on the command line
    * to an entry from the above list...
    */
-  int lencode = strlen( request );
-
-  int index;
-  for( index = 0; index < end_of_actions; index++ )
+  if( request != NULL )
   {
-    /* Try all defined keywords in turn, until we find a match
-     * or we run out of definitions...
-     */
-    if( strncmp( request, action_name( index ), lencode ) == 0 )
+    int lencode = strlen( request );
+
+    int index, retval, matched;
+    for( index = matched = 0; index < end_of_actions; index++ )
+    {
+      /* Try all defined keywords in turn, until we run out
+       * of definitions.
+       */
+      if( (strncmp( request, action_name( index ), lencode ) == 0)
+       /*
+        * When we find a match, and it is the first...
+        */
+      &&  (++matched == 1)  )
+       /*
+        * ...then we record as the probable index to return.
+        */
+       retval = index;
+    }
+    if( matched > 1 )
       /*
-       * for a successful match...
-       * immediately return the associated action code index.
+       * We matched more than one valid keyword; reject them all.
        */
-      return index;
+      dmh_notify( DMH_ERROR, "%s: action keyword is ambiguous\n", request );
+    
+    else if( matched == 1 )
+      /*
+       * We matched exactly one keyword; return its index value.
+       */
+      return retval;
   }
-
-  /* If we get to here, the specified keyword was not matched;
+  /* If we get to here, the specified keyword was not uniquely matched;
    * signal this, by returning -1.
    */
   return -1;