Bug 1562115 - Prevent cutting off long stub installer text strings. r=agashlin

This patch copies over the same fix that was used for the profile cleanup page
to the installing page, since in some locales it can run into the same problem
of the header string being so long that it causes the next control to get cut
off by the bottom of the window.

Differential Revision: https://phabricator.services.mozilla.com/D36523

--HG--
extra : moz-landing-system : lando

browser/branding/official/branding.nsi

@@ -45,6 +45,7 @@
 !define INSTALL_HEADER_TOP "70u"
 !define INSTALL_HEADER_LEFT "22u"
 !define INSTALL_HEADER_WIDTH "180u"
+!define INSTALL_HEADER_HEIGHT "100u"
 !define INSTALL_BODY_LEFT "22u"
 !define INSTALL_BODY_WIDTH "180u"
 !define INSTALL_INSTALLING_TOP "115u"

browser/installer/windows/nsis/stub.nsi

@@ -845,10 +845,21 @@ Function createInstall
     ${DialogUnitsToPixels} ${INSTALL_HEADER_WIDTH} X $0
     ${GetTextWidthHeight} "$(STUB_INSTALLING_HEADLINE)" $FontHeader $0 $R1 $R2
     ${ConvertLeftCoordForRTL} ${INSTALL_HEADER_LEFT} $0 $9
+    ; If this text is over the maximum height, drop the font size until it fits.
+    StrCpy $4 $FontHeader
+    !ifdef INSTALL_HEADER_HEIGHT
+      ${DialogUnitsToPixels} ${INSTALL_HEADER_HEIGHT} Y $2
+      StrCpy $3 ${INSTALL_HEADER_FONT_SIZE}
+      ${While} $R2 > $2
+        IntOp $3 $3 - 2
+        CreateFont $4 "$FontFamilyName" $3 ${INSTALL_HEADER_FONT_WEIGHT}
+        ${GetTextWidthHeight} "$(STUB_INSTALLING_HEADLINE)" $4 $0 $R1 $R2
+      ${EndWhile}
+    !endif
     ${NSD_CreateLabel} $9 ${INSTALL_HEADER_TOP} $0 $R2 \
       "$(STUB_INSTALLING_HEADLINE)"
     Pop $0
-    SendMessage $0 ${WM_SETFONT} $FontHeader 0
+    SendMessage $0 ${WM_SETFONT} $4 0
     SetCtlColors $0 ${COMMON_TEXT_COLOR} transparent
   !endif