Avoid creation of unnecessary image bufs (at alt-text to img switch)

This is the first of a patch series for image code bugs that have
severe impact on performance.

With these testing files:

1imgA.html  =  <img src="maj00s.png" alt="img1">
2imgSA.html  = <img src="maj00s.png" alt="img1">
               <img src="maj00s.png" alt="img12">
3imgSA.html  = <img src="maj00s.png" alt="img1">
               <img src="maj00s.png" alt="img12">
               <img src="maj00s.png" alt="img123">

2imgA.html  =  <img src="maj00s.png" alt="img1">
               <img src="maj21s.png" alt="img12">
3imgA.html  =  <img src="maj00s.png" alt="img1">
               <img src="maj21s.png" alt="img12">
               <img src="c10s.png" alt="img123">

This are the results:

.------------------------------------------------------------------.
|imgbufs     |         No patch         |         Patched #1       |
|            | first time | upon reload | first time | upon reload |
|-------------------------------------------------------------------
|1imgA.html  |     2      |     1       |     1      |      1      |
|2imgSA.html |     3      |     2       |     1      |      2      |
|3imgSA.html |     4      |     3       |     1      |      3      |
|-------------------------------------------------------------------
|2imgA.html  |     4      |     2       |     2      |      2      |
|3imgA.html  |     6      |     3       |     3      |      3      |
'------------------------------------------------------------------'

3 files changed, 10 insertions, 6 deletions

diff --git a/src/dicache.c b/src/dicache.c
index db3b86b2..b63e9d3b 100644
--- a/src/dicache.c
+++ b/src/dicache.c
@@ -256,7 +256,9 @@ void a_Dicache_invalidate_entry(const DilloUrl *Url)
 
 /*
  * Set image's width, height & type
- * (By now, we'll use the image information despite the html tags --Jcid)
+ * - 'width' and 'height' come from the image data.
+ * - HTML width and height attrs are handled with setNonCssHint.
+ * - CSS sizing is handled by the CSS engine.
  */
 void a_Dicache_set_parms(DilloUrl *url, int version, DilloImage *Image,
                          uint_t width, uint_t height, DilloImgType type,
@@ -269,7 +271,7 @@ void a_Dicache_set_parms(DilloUrl *url, int version, DilloImage *Image,
    /* Find the DicEntry for this Image */
    DicEntry = a_Dicache_get_entry(url, version);
    dReturn_if_fail ( DicEntry != NULL );
-   /* Parameters already set? */
+   /* Parameters already set? Don't do it twice. */
    dReturn_if_fail ( DicEntry->State < DIC_SetParms );
 
    _MSG("  RefCount=%d version=%d\n", DicEntry->RefCount, DicEntry->version);
diff --git a/src/html.cc b/src/html.cc
index c4033ca6..f465f888 100644
--- a/src/html.cc
+++ b/src/html.cc
@@ -1800,8 +1800,8 @@ static void Html_tag_open_style(DilloHtml *html, const char *tag, int tagsize)
 static void Html_tag_close_style(DilloHtml *html)
 {
    if (prefs.parse_embedded_css && html->loadCssFromStash)
-      html->styleEngine->parse(html, html->base_url, html->Stash->str, html->Stash->len,
-                               CSS_ORIGIN_AUTHOR);
+      html->styleEngine->parse(html, html->base_url, html->Stash->str,
+                               html->Stash->len, CSS_ORIGIN_AUTHOR);
 }
 
 /*
diff --git a/src/image.cc b/src/image.cc
index 9915023a..97270eef 100644
--- a/src/image.cc
+++ b/src/image.cc
@@ -106,9 +106,11 @@ void a_Image_set_parms(DilloImage *Image, void *v_imgbuf, DilloUrl *url,
                        int version, uint_t width, uint_t height,
                        DilloImgType type)
 {
-   _MSG("a_Image_set_parms: width=%d height=%d\n", width, height);
+   _MSG("a_Image_set_parms: width=%d height=%d iw=%d ih=%d\n",
+        width, height, Image->width, Image->height);
 
-   bool resize = (Image->width != width || Image->height != height);
+   /* Resize from 0,0 to width,height */
+   bool resize = true;
    I2IR(Image)->setBuffer((Imgbuf*)v_imgbuf, resize);
 
    if (!Image->BitVec)