Fix bug in --list operation due to concurrent i/o on input.

This also cleans up the termination of the read thread for those
cases where the entire input was not read, but the read thread is
no longer needed.

pigz.c

@@ -2472,7 +2472,8 @@ local void single_compress(int reset)
 /* --- decompression --- */
 
 #ifndef NOTHREAD
-/* parallel read thread */
+/* parallel read thread -- if the state is 1, then read a buffer and set the
+   state to 0 when done, if the state is > 1, then end this thread */
 local void load_read(void *dummy)
 {
     size_t len;
@@ -2484,7 +2485,11 @@ local void load_read(void *dummy)
     try {
         do {
             possess(g.load_state);
-            wait_for(g.load_state, TO_BE, 1);
+            wait_for(g.load_state, NOT_TO_BE, 0);
+            if (peek_lock(g.load_state) > 1) {
+                release(g.load_state);
+                break;
+            }
             g.in_len = len = readn(g.ind, g.in_which ? g.in_buf : g.in_buf2,
                                    BUF);
             Trace(("-- decompress read thread read %lu bytes", len));
@@ -2496,6 +2501,17 @@ local void load_read(void *dummy)
     }
     Trace(("-- exited decompress read thread"));
 }
+
+/* wait for load_read() to complete the current read operation -- if the
+   load_read() thread is not active, then return immediately */
+local void load_wait(void)
+{
+    if (g.in_which == -1)
+        return;
+    possess(g.load_state);
+    wait_for(g.load_state, TO_BE, 0);
+    release(g.load_state);
+}
 #endif
 
 /* load() is called when the input has been consumed in order to provide more
@@ -2524,9 +2540,7 @@ local size_t load(void)
         }
 
         /* wait for the previously requested read to complete */
-        possess(g.load_state);
-        wait_for(g.load_state, TO_BE, 0);
-        release(g.load_state);
+        load_wait();
 
         /* set up input buffer with the data just read */
         g.in_next = g.in_which ? g.in_buf : g.in_buf2;
@@ -2568,6 +2582,33 @@ local size_t load(void)
     return g.in_left;
 }
 
+/* terminate the load() operation -- empty buffer, mark end, close file (if not
+   stdin), and free the name obtained from the header, if any */
+local void load_end(void)
+{
+#ifndef NOTHREAD
+    /* if the read thread is running, then end it */
+    if (g.in_which != -1) {
+        /* wait for the previously requested read to complete and send the thread a
+           message to exit */
+        possess(g.load_state);
+        wait_for(g.load_state, TO_BE, 0);
+        twist(g.load_state, TO, 2);
+
+        /* join the thread (which has exited or will very shortly) and clean up */
+        join(g.load_thread);
+        free_lock(g.load_state);
+        g.in_which = -1;
+    }
+#endif
+    g.in_left = 0;
+    g.in_short = 1;
+    g.in_eof = 1;
+    if (g.ind != 0)
+        close(g.ind);
+    RELEASE(g.hname);
+}
+
 /* initialize for reading new input */
 local void in_init(void)
 {
@@ -2983,13 +3024,18 @@ local void list_info(void)
     /* read header information and position input after header */
     method = get_header(1);
     if (method < 0) {
-        RELEASE(g.hname);
         if (method != -1 && g.verbosity > 1)
             complain(method != -6 ? "skipping: %s not compressed" :
                      "skipping: %s corrupted: invalid header crc", g.inf);
         return;
     }
 
+#ifndef NOTHREAD
+    /* wait for read thread to complete current read() operation, to permit
+       seeking and reading on g.ind here in the main thread */
+    load_wait();
+#endif
+
     /* list zip file */
     if (g.form > 1) {
         g.in_tot = g.zip_clen;
@@ -3080,7 +3126,6 @@ local void list_info(void)
 
     /* list information about contents */
     show_info(method, check, len, 0);
-    RELEASE(g.hname);
 }
 
 /* --- copy input to output (when acting like cat) --- */
@@ -3771,17 +3816,14 @@ local void process(char *path)
     SET_BINARY_MODE(g.ind);
 
     /* if decoding or testing, try to read gzip header */
-    RELEASE(g.hname);
     if (g.decode) {
         in_init();
         method = get_header(1);
         if (method != 8 && method != 257 &&
                 /* gzip -cdf acts like cat on uncompressed input */
                 !(method == -2 && g.force && g.pipeout && g.decode != 2 &&
                   !g.list)) {
-            RELEASE(g.hname);
-            if (g.ind != 0)
-                close(g.ind);
+            load_end();
             if (method != -1)
                 complain(method < 0 ?
                             method != -6 ? "skipping: %s is not compressed" :
@@ -3810,19 +3852,15 @@ local void process(char *path)
                 drop(err);
                 outb(&g, NULL, 0);
             }
-            RELEASE(g.hname);
-            if (g.ind != 0)
-                close(g.ind);
+            load_end();
             return;
         }
     }
 
     /* if requested, just list information about input file */
     if (g.list) {
         list_info();
-        RELEASE(g.hname);
-        if (g.ind != 0)
-            close(g.ind);
+        load_end();
         return;
     }
 
@@ -3886,9 +3924,7 @@ local void process(char *path)
         if (g.outd < 0 && errno == EEXIST) {
             complain("skipping: %s exists", g.outf);
             RELEASE(g.outf);
-            RELEASE(g.hname);
-            if (g.ind != 0)
-                close(g.ind);
+            load_end();
             return;
         }
 
@@ -3897,7 +3933,6 @@ local void process(char *path)
             throw(errno, "write error on %s (%s)", g.outf, strerror(errno));
     }
     SET_BINARY_MODE(g.outd);
-    RELEASE(g.hname);
 
     /* process ind to outd */
     if (g.verbosity > 1)
@@ -3937,8 +3972,7 @@ local void process(char *path)
     }
 
     /* finish up, copy attributes, set times, delete original */
-    if (g.ind != 0)
-        close(g.ind);
+    load_end();
     if (g.outd != -1 && g.outd != 1) {
         if (close(g.outd))
             throw(errno, "write error on %s (%s)", g.outf, strerror(errno));
@@ -4314,6 +4348,9 @@ int main(int argc, char **argv)
         /* initialize globals */
         g.inf = NULL;
         g.inz = 0;
+#ifndef NOTHREAD
+        g.in_which = -1;
+#endif
         g.outf = NULL;
         g.first = 1;
         g.hname = NULL;